The identity of EU national
Besides, the derogation may be imposed by the host State under Article 45(3) TFEU, and the restrictions on the right of entry and right of residence by Latvia based on the ground of public health, public policy and public security as stated in Article 27 and 29 of Directive 2004/38/EC.
In addition, Article 39 EC Treaty has secured the workers whether employees or self-employed, or at any rate as economically active persons,  who ‘migrate’ within the Community to exercise of freedom of movement in the context of the common market.  There should be an equal treatment between persons despite of racial or ethnic origin. In Levin v Staatssecretaris van Justitie,  its principle is the work has to be “genuine and effective" economic activity which must not be on such a small scale as to be “purely marginal and ancillary." Therefore, the UK citizen and his partner may be treated as “work-seekers", because they have not get any employment offers in Latvia yet, but they still can enter to Latvia to seek work and stay there for a reasonable period of time, based in ex parte Antonissen.  They can rely on Article 6(1) Directive 2004/38/EC which provides that EU citizens shall have the right of residence in another Member State for a period of up to three months without any conditions or formalities other than the requirement to hold a valid identity card or passport.
There have few issues need to be pinpointed, like based on the ground of cousin of the UK citizen’s partner past criminal conviction, entry of him whether will be refused by Latvia, also the rights to benefits, assistance of university education and claim for job seeker’s allowance. Essentially, he is EU citizen under Article 20 TFEU, and he is regarded as non-economically active person in Article 7 of Directive 2004/38/EC. He also can exercise the right of exit and entry under Article 4 and 5 of the same Directive.
Despite of this, Latvia may restrict on his right of entry and the right of residence on the ground of his past criminal conviction and apply the derogation under Article 45(3) TFEU, but Article 27(2) of Directive 2004/38/EC provides that previous criminal convictions shall not be taken into account, as shown in the case of Van Duyn.  So, the element may be taken into consideration is his personal conduct must represent a “genuine, present and sufficiently serious threat affecting the society,"  based in Bouchereau’s case.  Latvia has discretion to request his country of origin to provide information in relation to his conviction.  It is arguable that he does not create any serious threats affecting the society, and he has the right to enter and reside in Latvia. He also can exercise the fundamental principle of enjoyment of equal treatment with Latvia citizens under Article 24(1) of the same Directive by applying the case of Cowan v Tresor Public,  , and he should not be prejudiced due to his past criminal conviction under Article 18 TFEU. Another thing, he may have the right to get assistance on education in Latvia under Article 12 of Regulation 1612/68, where the family member of migrant workers similarly are entitled to equal treatment in respect of the social advantages like education. In the case of Bidar v Ealing London Borough Council,  two things should be distinguished, which are the object of the financial support and the capacity in which persons may be eligible for financial support. By applying the case of Maria Teixeira,  the right of residence of the UK citizen’s partner who is the “primary carer"  for him in education, ends in principle when he is presumed to become self-sufficient, unless it is established that he needs cousin’s financial help to pursue his education.  The death of his parents caused him relying on his cousin since he was nine years old, he has to show that he is not a burden on the social assistance system. Therefore he may be granted assistance with the tuition fees for his course of studies at Latvia University as it has to be under equal conditions to students from all Member State, supporting by the cases of Gravier v City of Liège  and Raulin v Minister van Onderwijs en Wetenschappen. 
Another issue in relation to the jobseeker’s allowance, by applying the test in Regulation 85(4) of the Jobseeker's Allowance Regulations 1996, Latvia may refuse him for the claim on the ground that he is not habitually resident in the Latvia, in the case of Collins.  Under Article 14(4)(b) of Directive 2004/38/EC, there should be an evidence of a person continue to seek employment actively and a genuine chance of being engaged which is subject to questions of justification and proportionality.
There have few matters need to be examined, like freedom of establishment is subject to the UK citizen, whether the need for taking up the aptitude test if the UK citizen wants to practise in Latvia and the free movement of services under the provision of Article 49 TFEU in relation to his partner’s brother to set up his internet business.
Firstly, the UK citizen had taken BPTC and will be treated as a qualified lawyer if he practises in UK, this is where the Member States are prohibited of discrimination under Article 49 TFEU which is directly effective, as shown in Reyners v Belgian State. The court in Gebhard v Milan Bar Council  had characterized the “establishment" as the right of a community national to participate on a stable and continuous basis in the economic life of a Member State other than his or her own “services" by the temporary, precarious and discontinuous nature of the services.  Therefore, as a practising lawyer in Latvia, he may subject to Lawyers Directive 77/249. However, it limits the recognition of practising lawyers from Member States, who must be accepted based on understanding that the training if lawyers in other Member States is similarly strict as in the host State. There have four conditions need to be satisfied for the exercise of fundamental freedoms, such as non-discriminatory in application, justified by imperative reason relating to the public interest, suitable to secure the objective sought and proportionate.  In addition, by applying the case of Vlassopoulou,  Latvia must take into account his qualifications and experience in UK to check out whether it is equivalent to the national requirements. It is arguable that he can practise in Latvia under his home country professional title under Lawyers Home Title Directive 98/5 provides under Article 2 and he needs only to register with the competent authority in Latvia on the basis of tthe recognition in UK under Article 3 as well. Based on Morgenbesser,  Latvia is obliged to compare his professional knowledge within the state. Under Article 4(2), it mentions the lawyers providing services in judicial proceedings are required to observe both those sets of rules of professional conduct of the home and host State. He may need to take up the aptitude test and practise as a barrister, as stated under Lawyers Home Title Directive 98/5.
In the case of his partner’s brother, who is EU citizen under Article 20 TFEU, needs to establish himself in Latvia in order to provide service, under Article 49 TFEU. Latvia has to consider whether the opening of the internet based company and the individual business rules are inconsistent with the national law. But there should be no prohibition on the restriction of freedom to provide services within the Union under Article 56 TFEU. In the case of Webb,  the court makes clear that a person is allowed to provide the activity in the Member State where the service is given without suffering discrimination in favour of the nationals of the State. It may be argued that Latvia has to take all appropriate measures to ensure fulfilment of the obligations arising out of Article 9 and 10 TFEU. The free movement of goods is vital in the Single Market and the European Commission is vigilant to make sure the free movement provisions as in the Treaty. A formula has been designed to weigh the balance between trade integration and local regulatory concerns, in Cassis de Dijon.  The case of Stichting Collective Antennevoorziening  also states that the cultural policy constitutes a requirement in the general interest justifying a restriction on the freedom to provide services. However, it is submitted that under Article 34 TFEU, prohibits quantitative restrictions and all measures having equivalent effect on imports.
Commission v Italy  defined goods as "products which can be valued in money and which are capable, as such, of forming the subject of commercial transactions." Therefore, contact lenses are treated as "goods" in this dispute. To answer the question raised, the Court must determine the provisions of EU law applicable to the sale of contact lenses over the internet.
Latvia may argue that the lenses come into direct contact with the eyes and can cause eye inflammations, so the restriction of internet advertisement is permissible for policy reasons and ensuring the health of contact lenses wearers is protected.  The Member States have to identify the level of protection in the field of public health which they wish to afford to public health and the way in which that level is to be achieved, as shown in joined cases Blanco Pérez and Chao Gómez.  Therefore the requirement of an optician to issue a prescription for lenses may be justified.
However, Latvia’s legislation prohibiting the selling of contact lenses over the internet which concerns a selling arrangement must be examined under Articles 34 and 36 TFEU. CJEU in Van Gend en Loos  stressed that Article 30 had direct effect and created individual rights which national courts must protect. Thus, the UK partner’s brother should have a protection of individual rights where Latvia should not difficult him to supply contact lenses over internet. Latvia exceeds the limits of the discretion and its legislation has gone beyond what is necessary to reach the aim the Member State claims to keep going but can protect the health of its citizens and allow cross border trade in lenses. Therefore, Latvia’s legislation may violate Article 34 and it is not justified.
The UK partner’s brother may want to know whether it is justifiable to charge him for inspections, warehousing, and higher VAT rates on contact lenses. First thing needs to be established is the contact lenses are goods which cross over the borders, constitutes a charge having an effect equivalent to a customs duty. The Member States are prohibited to impose customs duties on imports and exports and charges having equivalent effect, and also custom duties of a fiscal nature, as stated in Article 30 TFEU. There have few criteria for inspection need to be satisfied under Commission v Germany  such as the inspection of contact lenses is mandatory under EU Law, imposed across the EU, charge is proportionate to the cost of providing the inspection and in the general interest of free movement of goods.  So, he may argue that the charges of €100 per pallet-load of lenses exceed the cost of inspections and Latvia may breach the article. Further, there has a restriction of indistinctly applicable measures on the lenses imports from other Member State, the partner’s brother will now be subject to the rule of reason under Cassis de Dijon and may apply Article 36 TFEU to distinctly applicable measures. If indistinctly applicable measures are clearly discriminatory in Member State’s effect on imports or fall within one of the derogations of the article, the court may consider the question of justification. Therefore even if a measure is justifiable under one of the derogations of Article 36, it must not “constitute a means of arbitrary discrimination or a disguised restriction on trade between Member States." 
Under Article 110 TFEU, the Member States should not impose any internal taxation on similar domestic products. The article intends to prevent any States from imposing a tax on products which discriminate against imported products or inadvertently protect domestic products. In Commission v UK, CJEU said that wine and beer were similar and that the differential in taxation amounted to the discrimination contrary to Article 110(1). Therefore back to the dispute, it can be said that contact lenses and spectacles are similar as both of them is to correct the defective vision, so Latvia should not impose different taxation as they may violate the article. However, Latvia may argue the issue of national interest under the case of Haahr Petroleum  where they attempt to protect their domestic products in the spectacle industry, thus they are able to impose higher VAT rates on contact lenses. In addition, based in Vinal v Orbat,  CJEU allowed higher taxation on products even where the categories of products are largely imported, if the differential can be objectively justified.  It is submitted that there is a weak advantage because the court now has introduced some mandatory requirements, like the protection of consumers in The German Beer Case  and the diversity of the press in Familiapress v Bauer Verlag.  In the further case of Cassis de Dijon,  the court established the principle of mutual recognition, like where a product is lawfully marketed in one Member State, there is a presumption that it could be sold in other Member States without any further impediments to free trade. Latvia should not impose a higher VAT rate on contact lenses according to Article 30 TFEU.
Another issue is the cost of warehouse in Latvia, €100 per week. This is justified on the grounds that it is necessary for the adequate monitoring and inspection of imported lenses. Where there is no Community harmonisation, the Member States has discretion to set their levels of protection. Back to this dispute, under Commission v Italy,  the partner’s brother may argue under charges having equivalent effect, even if Latvia does not impose for the benefit of the State and they should not impose unwanted service like warehouse charge but supposed to be paid by the government. Supporting by Commission v Belgium,  the CJEU held that charges for customs clearance constitutes charges having an equivalent effect if they are imposed solely in connection with the completion of customs formalities. However, Latvia may say this is a permissible charges but not charges having equivalent effect. There have few criteria for a genuine service, the first thing is whether the charge of €100 per week is proportionate or no. If it does not exceed the cost of service, then he is said to be charged lawfully, but the right rate should be divided by seven days if he places the lenses in the warehouse less than a week. The second thing, it must be genuine or specific benefit. Since he does not have any options due to the inspection regime and the delay, he forced to oblige Latvia’s government command and so placed the lenses in the warehouse with the charges, thus the service is treated as not genuine. The final thing is there must be an obvious benefit to the trader like him. It is clear that such scenario is benefited Latvia and the public from inspection. Consequently, the fee for service should be borne by the government.