Nick Clegg issues challenge over Europe in Lib Dem speech
Liberal Democrat leader Nick Clegg has pledged to take on "backwards-looking politics", as he made the case for membership of the EU in a speech.
The deputy prime minister acknowledged reform was needed but stressed the UK could not demand changes with "one foot out of the door".
"Pulling up the drawbridge" would damage the economy, he said, as he used his party conference speech to build up to next month's EU election debates.
The elections take place in May.
In his closing speech to the Lib Dem spring conference in York, Mr Clegg portrayed the elections as a straight choice between his party and critics of the EU.
He warned against a "stuffy parochialism dressed up as patriotism", saying: "Forget the lazy assumption that, in the court of public opinion, the Eurosceptics will automatically win. There is nothing automatic about election results," he said.
He argued that people wanted "hope" when it came to remaining in Europe.
"There are plenty of people out there who don't want anger. They don't want bile. They want jobs. They want our country to have influence," he said.
Making his case for retaining close links with Europe, he said the global financial crisis had "created an entirely understandable but dangerous urge to turn inwards".
Mr Clegg is to take on UK Independence Party leader Nigel Farage, whose party wants to take the UK out of the EU, in two debates next month.
Turning his focus to UKIP, he said an "ungenerous, backwards-looking politics has emerged in Britain".
"The politics of blame has found an acceptable face: It wears a big smile and looks like someone you could have a pint with down the pub.
"So I'm drawing a line in the sand. I am going to defend the tolerant and modern Britain we love, and I am going to start by showing people what's at stake at the upcoming European elections: Do you want Britain in Europe, or out?
"That's the real question in May. One party wants out. Another is flirting with exit. The other lot don't have the courage of their convictions on this - they're saying nothing at all.
"The Liberal Democrats are now Britain's only party of in. The only party out there explaining the clear benefits of Britain's place in Europe. The only party giving people the facts."
Prime Minister David Cameron has set out plans to renegotiate the UK's links with Brussels and hold an in/out referendum on EU membership by the end of 2017.
Setting out why the Lib Dems are for remaining in the EU, Mr Clegg said Europe was the UK's biggest export market and vital to British jobs, adding "because pulling up the drawbridge is the surest way to wreck our economic recovery".
He said leaving the EU would also make it harder to catch international criminals and hamper efforts to tackle climate change.
"But you can't change it with one foot out the door. You change it by taking your place at the table - which is where you protect Britain's national interest too," Mr Clegg said.
He will also spell out the extent of his party's influence during its time in government, saying: "There would be no recovery without this party."
"Don't let anyone airbrush out our role," he said.
"And no matter what our critics say, when the history books are written they will say that, most extraordinary of all, the country was put back on the right track by a party which had never been in government before but which had the guts and the courage to do what it took."
Mr Clegg's speech comes as the Lib Dems continue to struggle in the opinion polls, often being placed fourth, behind UKIP, in recent months.
But Lib Dem president Tim Farron said it was vital to make the argument for staying in the EU, telling BBC 5 Live: "Three million British jobs depend on our membership of the European Union, our ability to track, trace and then catch criminals across borders depends on the European Union, our ability to tackle climate change depends on our ability to work with our colleagues across the European Union.
"And indeed there's been 70 years of peace and security because of cooperation across borders in Europe."
But UKIP argues that being in the EU makes it impossible for the UK to control immigration levels and that Brussels over-regulates UK industry and damages its competitiveness.
For Labour, deputy leader Harriet Harman said: "Far from holding back the Tories, Nick Clegg and his Liberal Democrats have broken their promises and backed the Tories all the way and hardworking people are paying the price."