Direct effect is a concept derived from the jurisprudence of the Eu
Van Gend en Loos raised issues surrounding the prohibition of raising import taxes, by member states to the treaty.  The Dutch government in breach of its obligation raised import tax. Mr. Van Gend en Loos, significantly, in his individual capacity sought to rely on Article 25. The Advocate General decided that enforcement of community law was for the Commission or member states, and not for individuals. The ECJ however, disagreed.  It was held that community law not only imposes obligations on individuals, but confers rights upon them.’ 
This decision has been considered a landmark, for EU law in two respects. Namely, that it established the doctrine of supremacy and secondly it gave rise to direct effect. Both concepts were considered ‘foreign’ to member states of the treaty.
The commencement of the doctrine of direct effect is therefore traced back to its ‘birth’ in the case of Van Gend en Loos. Interestingly, Van Gend en Loos concerned the enforcement of an Article. However, the decision was further instrumental in the development of the conditions necessary to obtain direct effect.
Three conditions were provided by the ECJ as necessary for its enforcement. 
1. The provision being relied upon must be clear and unambiguous.
The provision must be unconditional.
The provision must not be dependent on further action by the member state. That means the provision must be a negative as opposed to a positive obligation.
However, the ECJ were to change their stance on the three conditions in later case law.  The case of Defrenne concerned a positive obligation on a member state, imposed by an Article.  The ECJ held that despite the Van Gend criteria not being met, an individual can still enforce community law, via the doctrine of direct effect where a deadline of implementation has been provided, and that deadline has past without the member state acting.
The ECJ seemingly adapted established conditions in order to ensure the effectiveness of community law. It is argued that such activism creates legal uncertainty, as to the Court’s role and also a member states’ roles. It is further suggested that conditions are simply irrelevant, and that with or without them the Court will manoeuvre the obstacles to enforce community law.  0 Therefore, it seems that the law in this area is far from certain. It has however allowed for the furtherance of community remedies.  1
As the doctrine of direct effect has developed, so to have the criticism toward the ECJ increased. It is academically argued that there is no place for such judicial activism in the European Community.  2 This is because the ECJ were never granted such powers to create such doctrines.  3However, it has been suggested that if such activism creates rights for individuals it should be accepted.  4 In response Capeletti argues that an impact study of a positive outcome is not justification for the activism.  5 He suggests that it is justified because the Court is in the best possible position to enforce rights.  6 Both academics however, seem to miss a fundamental point. The purpose of the community was and still is economics. By granting rights to individuals the ECJ maintain the purpose of the Community. By generating more remedies, the economy is reinforced by individuals, who may not be deterred as perhaps fellow member states and the commission might be, due to international relationships and political affiliation.
The growth of direct effect, has ventured from Articles into the realm of Directives. A Directive is binding as to the result to be achieved and unlike regulations they are not specified to have direct effect. However, the ECJ once again altered the ‘playing field’.  6 It held in Grad that just because some provisions were identified, as having direct effect, does not prevent others from being so, that were not specified as being of imposing the doctrine.  7
It is arguable that if the ECJ is not being judicially active i.e they are simply enforcing Community values; it is arguable that they are redrafting the EC Treaty. However, the ECJ did draw the line on Directives at vertical direct effect.  8 That is between the state and an individual. They were not willing to extend the doctrine to horizontal disputes i.e between individuals.  9 This in turn has given rise to further remedies. It has been argued that the curtailment on Directives is due to the prevention of risking national sensitivities.  0 But this argument seems flawed because the ECJ has not been concerned with national sensitivities in creating many of its doctrines. The pronouncement of supremacy and direct effect saw no concern for it.  1 I think that the move related primarily to enforcing community law against states. There is less value, economically, in enforcing EC law against individuals.
The ECJ has further utilised remedies to circumvent the shortcomings of direct effect.  2 Done by evoking an established Community obligation and implying it to the facts before them.  3 Where indirect effect is not possible, the ECJ has been willing to find state liability.  4 In the case of Francovich, an individual was left without a remedy, despite Italy being found in breach of its Community obligations by the Commission. It was determined that in order to gain damages, an individual must demonstrate a serious breach, and disregard for the limits of its discretion.  5 It seems that the ECJ are willing to enforce the objectives of the treaty, by stretching doctrines and establishing new ones. The definition of a state is an example of the desire to retain economic growth, by including it to mean any public body.  6
Triangular situations have also operated to create a further remedy.  7 A triangular situation arises where two private parties invoke a Directive, imposing an obligation on a state that also effects the legal position of third parties.  8 Although a number of remedies appear to have arisen due to the inadequacies of direct effect in relation to horizontal disputes regarding Directives, this however is not so. It seems that many of the remedies were unnecessary due to the 2005 case of Mangold v Helm.  9
In Mangold a worker was dismissed (based on their age) one day before the implementation of an equal treatment directive. The case, interestingly, concerned two private individuals, which was largely ignored by the court. It was held that the directive could be enforced by direct effect, and could be enforced one day before its implementation.
The case raises a number of concerns and criticisms. For as it can be seen the Van Gend and Sabena criterion were ignored and changed again. Furthermore, the issue of horizontal effect no longer appears to be an issue, in regards to age discrimination Directives at the very least. Therefore it appears that community law is in a compromising and uncertain position. The law demands certainty, and inconsistency is not a way of achieving it. But perhaps it is arguable that where Community law values are undermined, the Court will do its utmost to remedy the situation. It seems that the agenda remains one of economics and reinforcement of Community values.