In the construction of the European Union institutions, the principles of subsidiarity, principles of proportionality and principles of supremacy were laid down. These had a function of streamlining decision-making in the Union and since they were binding, they were entrenched in the treaties that were signed during that time. Treaties that came later on only strengthened these principles. Application of EU powers is regulated by the principles of proportionality and subsidiarity.
Under legislation and execution, the principles of supremacy rank the Union's rules and regulations higher than the national laws in the judicial hierarchy. Principles of subsidiarity permit the EU to act only in areas where its goals could not be realized sufficiently by member countries. The European Union could have been a better level for this, even though the central, regional or local levels could also serve as avenues. It implies that the principle points to situations where the Union or member countries could act and not in areas where the Union has absolute powers. The principles of proportionality constrain the EU from controlling more than what is functionally required and permitted by the treaty. This implies that no type of EU function or its substance should extend its control any further than what is required to achieve the purpose of the treaty. The European Court of Justice determines disputes arising from the application of these principles.
The treaty of Lisbon, sometimes referred to as the European Union Reform Treaty accorded the European Parliament a much significant role. It will be charged with the responsibility of electing the Commission's president. In collaboration with the Council, it will apply the legislative and the budgetary powers along with consultations as enshrined in the treaty. Composition of this parliament will be such that national representation would be in proportion to the population, however smaller member countries will be accorded favorable treatment. There will be a maximum number of 750 members together with its president.
