Nick Clegg and Nigel Farage trade blows on voting records as they warm up for two head-to-head later this month

Nick Clegg and Nigel Farage have already begun the verbal sparring (PA)

Nick Clegg clashed with Nigel Farage today as they rehearsed their lines for two head-to-head debates before the European Parliament elections in May.

The Liberal Democrat and UK Independence Party leaders will do battle in a radio debate on LBC 97.3 on 26 March, hosted by Nick Ferrari, and a televised debate on BBC2 on 2 April, hosted by David Dimbleby.

Mr Clegg has adopted a high-risk strategy before the EU elections, declaring that the Lib Dems are the “party of IN” in a deliberate contrast with Ukip, which wants Britain to pull out. He hopes his boldness will contrast with what he calls Labour’s decision to sit on the fence and the Conservatives’ attempt to woo Ukip supporters by talking tough.

After the two broadcasters signed up to the two hour-long “Nick versus Nigel” debates yesterday, Mr Clegg predicted a “lively contest.” He added: "I am delighted that it has been confirmed that these debates will now definitely happen. I'm relishing the prospect of talking about how the Lib Dems are fighting to keep Britain in Europe to protect British jobs while Ukip want to yank us out and threaten our recovery."

In a speech today, Mr Clegg accused Ukip members of the European Parliament of letting Britain down by not bothering to turn up for key debates to press the case for EU reform.

He told the Centre for European Reform think-tank: “You would have thought that if your world view was based on the idea that it has been bad for Britain for us to be part of the EU, a party such as the Ukip would have used its berth in the European Parliament to find every possible opportunity to promote reforms that create British jobs, enhance British security and that enhance the British way of life in the EU. Yet the record shows almost precisely the reverse. Ukip leaders don't turn up to vote most of the time.”

Mr Clegg claimed Mr Farage had not tabled a single amendment to the flow of legislation passing through the European Parliament since July 2009. "They [Ukip] have not only let down the case for the reform of the EU, they have let down British interests within the heart of the EU," he said.

The Deputy Prime Minister warned that David Cameron’s strategy to renegotiate the terms of Britain's membership and stage an in/out referendum in 2017 was “doomed to failure.” He said Mr Cameron would achieve only a "little tweak here, a little tweak there" and would never satisfy hardline Tory Eurosceptics who wanted either to withdraw from the EU or something very close to it. He claimed the Tories’ view was “misguided, mistaken and cannot be delivered”.

Hitting back, Mr Farage said Mr Clegg had “some cheek” in raising attendance and voting records because between 2010 and 2014 he has voted only 22.6 per cent of the time at Westminster even though he lives in London. "By contrast, I live eight hours away from Strasbourg, lead a national party and have voted 55 per cent of the time in the European Parliament.” He said some Ukip MEPs had a very high voting record, with Stuart Agnew on 91 per cent, Roger Helmer on 88 per cent and Derek Clark on 80 per cent.