The European Parliament is directly elected every five years. The last elections were in 2014 and the next will be in 2019. 73 of the 751 Members of the European Parliament (MEPs) are elected from Britain. This is equal to the number of MEPs from Italy and one less than France. Only Germany has a significant number more - 96. This is based entirely on population but it means no country alone can dominate the parliament but the UK has a significant voice.
Unlike elections for the UK Parliament, a proportional system is used. This means that 24 of our MEPs are from UKIP because that party did well in the 2014 elections. In the 2015 UK elections, the same party also did well, with nearly 13% of the vote, which gave them 1 MP under our system. Its worth reminding any UKIP supporter of that when they say the EU is undemocratic.
With a number of different groupings across 28 different counties, its no surprise that there is never one single group that can override all the others. This means nothing can be passed until a proper discussion is had.