The basic framework of United Kingdom (UK) immigration law - that is, the laws controlling the entry into, residence in and departure from the UK - is still provided by the Immigration Act 1971. This Act has been substantially amended and supplemented by several Acts including the Immigration Act 1988, the Asylum and Immigration Appeals Act 1993 and the Asylum and Immigration Act 1996, the Human Rights Act 1998 (HRA), the Immigration and Asylum Act 1999, and the Nationality Immigration and Asylum Act 2002.
While the various Immigration Acts provide the statutory basis for the control of immigration, the powers granted under the Acts are very general. How those powers are to be exercised is set out in much more detail in the Immigration Rules. These Rules attempt to be wide-ranging and fairly precise, and try to cover every conceivable type of application and state the requirements for each. The Immigration Rules are not in the form of legislation or secondary legislation, but they are set out in House of Commons Papers and come into force unless disapproved of by Parliament. They are not, therefore, exposed to detailed, parliamentary scrutiny. The Immigration Rules currently in force are included in House of Commons Paper No. 395.
The concern of this question can be seen as the application of human rights law in the UK in immigration making decisions.
On the 2nd of October 2000 came the commencement of the Human Rights Act which marked a new age. This was because human rights could be relied upon as the basis of legal argument offering the potential to give a greater equality of arms between the executive and the individual. However within the legal system human rights can only be utilised by individuals to the extent that rules of law permit the human rights argument. I.e. there is no point to having a right to say a private family life if no appeal body has declared it as being violated.
Having said this, just because human rights do exist, it does not mean that every issue in relation to it will be solved. This is because economic and political constraints may mean that human rights might not even save and individual from acute suffering, note N v SSHD  . Also the government may legislate to restrict rights as in s.55 of the Nationality, Immigration and Asylum Act  and the Criminal Justice and Immigration Bill  . This shows a clear interception of human rights which may leave people without redress as in AM v ECO Ethiopia  . This does not necessarily mean that it is discriminatory against immigrants because although human rights are an important step in bringing human interests and needs together legally, they are certainly not a cure for everyone’s legal problems as seen in AL (Serbia)  .
International human rights law has already played an important role in immigration cases even before the Human Rights Act came into force as there was a body of opinion that international human rights norms could be relied upon in UK courts. This was shown in R v Miah  where it was held a provision of the Immigration Act  could not have a retrospective effect.
However it can be seen that immigration law has been known to restrict human rights. An example of this came when the UK first ratified the ECHR in that it did not immediately grant the individual with a right to petition. This meant that although the UK was party to the Convention, no one in its jurisdiction could who suffered an infringement could complain. In 1966 the UK finally granted the right to petition, the delay being put down to the governments fear of applications from overseas terrorists, of which Britain had 42 in 1953 when the Convention was ratified  .
Immigration provisions are subject to the unique power in the Human Rights Act to declare legislation as incompatible. This power has been used in relation to the scheme for requiring the Secretary of State’s consent to the marriage of foreign nationals, which was declared incompatible with Article 12. The detention imposed on foreign terrorist suspects by the \Crime and Security Act 2001 was also declared incompatible as well as an improper use of immigration law.
The above can be seen in A v SSHD  , an apparent use of law to make immigration legislation fall in conflict with that of the human rights so those who come into contact with immigration legislation, most likely not British citizens, will find it difficult to be protected in the court of human rights.
Having said this with the advent of the Convention it became unlawful for public authorities to do anything that is contrary to their human rights. This includes the UK Government and its immigration departments and officers. It also includes private companies that are paid by the state to run immigration detention centres and asylum interviews.
The contents and protection of the Convention apply to every person in the UK, and within the influence of the UK authorities. Most importantly it also includes anyone granted temporary permission to remain in the UK, whether or not they had permission to enter in the first place as via Article 1 provides that such rights must be secured by everyone within that states boundaries. The only requirement to meet is that the applicant was directly affected by the issue in question.
What this also means is that anyone subject to an immigration decision has the right to appeal to the European Court of Human Rights, separate to the appeal system that they have under the UK laws already in place. Cases that have already been through the UK courts show that it is not possible for the immigration department to deport anyone if this would not be in line with the obligations of the UK under the Convention.
Immigration is a result of many things, the worst of which could be torture, degradation and inhumane treatment as a result of governments and local politics or religion. Article 3 of the Convention, and the UK’s own Human Rights Act, specifically prohibits such behaviour; therefore it would be unlawful for the UK immigration service to return any immigrant to their own country if there is a strong chance that they will have to face it, irrespective of any crimes they may have committed in the UK.
In addition to protection from abhorrent treatment under Article 2, immigrants who are being detained while applying for permission to stay in the UK must be treated in a way which protects their personal security and freedom; this comes under the wording of Article 5 of the convention. It is often used when determining whether or not their detention is in fact legal.
In addition to the above, the convention also provides protection for the families of immigrants. This is under the heading of a right to respect for family life, and can include more than immediate family (grandparents, aunts or uncles etc). Article 8 of the Convention specifically states that where there is no safe alternative country and/or insurmountable obstacles to relocation, or if the immigrant cannot return to their own country safely, then the family must be granted immigrant status. This right is not absolute and it can be prevented if it is deemed legitimate, for instance if the family member is a known terrorist or would present some other threat to public or national security.
This makes it look as though there are no apparent signs of discrimination. This is furthered with Article 14 which states;
“The enjoyment of the rights and freedoms set forth in this Convention shall be secured without discrimination on any ground such as sex, race, colour, language, religion, political or other opinion, national or social origin, association with a national minority, property, birth or other status."
Here it is apparent that the Article does not provide an independent or unconditional right not to be discriminated against. It is merely a prohibition of discrimination in the field of the ECHR; note Abdulaziz, Cabales and Balkandali v UK  . The scope of Article 14 will normally be narrower than the provisions of domestic law under the Race Relations Act  . This makes it unlawful for a public body to do any act that constitutes discrimination; however this is subject to a statutory defence of an authorised person acting in accordance to their job so it is possible that a form of discrimination will take place showing a clear conflict between Immigration legislation and human rights.
Previously present was a clear conflict of national law with immigration rules via the previous Race Relations Act of 1976 which controversially permitted discrimination in asylum, immigration and nationality matters on the basis of ethnic or national origins  .