MEPs are parliamentary giants. Don't snigger. There are many legitimate criticisms to be made of the European parliament, but irrelevance or lack of importance, the stock accusations, are laughably wide of the mark.

Probably half of all new legislation now enacted in the UK begins in Brussels. The European parliament has extensive powers to amend or strike down laws in almost every conceivable area of public life.

Like all legislatures, the parliament sometimes gets it wrong. It does not pay enough attention to the practical consequences of draft laws. It is a little trigger-happy in demanding new EU-wide regulation.

But the parliament most certainly isn't irrelevant or unimportant. In the four years I've been an MEP, we have adopted legislation stopping cosmetics being tested on animals, boosting recycling, forcing the French to open up their energy market, opening up travel for British pets, boosting the development of renewable energy and biofuels _ the list goes on.

It is no exaggeration to say that MEPs are now Europe's most influential lawmakers. The European parliament is blissfully free of overweening government majorities. Individual MEPs, regardless of party affiliation, exercise a degree of direct leverage over legislation unheard of in national parliamentary systems.

Yet the lack of interest in the European parliament among voters threatens its credibility. Reversing the lamentable voter turnout at next year's Euro-elections will be a defining moment.

Sadly, there's only so much that MEPs themselves can do about this. For sure, we must modernise our own working arrangements, not least by reversing the appalling vote last week stalling the overhaul of MEPs' pay and expenses.

But the underlying reasons for the European parliament's particular "democra tic deficit" go deeper. Electing an MEP to a legislative chamber across the Channel does not offer the same drama or clarity as a national election which can make or break governments.

As with so much in the EU, the European parliament suffers from a poverty of political leadership. Europe's leaders created it in the first place. Now they cannot simply disown their creation. Political leaders everywhere must make the case for Europe and its institutions where it counts, at home. Don't blame Brussels for voter apathy. Blame ourselves.

· Nick Clegg is a Liberal Democrat MEP for the East Midlands