Almost four out of 10 Liberal Democrat voters support leaving the EU, according to a new poll which shows that hardline euroscepticism has taken hold in Britain's most pro-European party.
An Opinium/Observer survey has found that 39% of Lib Dem supporters would be inclined to vote in favour of leaving Europe if an in/out referendum were called.
Overall, 56% of people surveyed would vote to leave the EU, while 29% would vote to remain. About 68% of Conservative and 44% of Labour want to leave, against 24% and 39% respectively who would stay in.
The results will fuel the growing political debate about Britain's place in the EU, which has seen even cabinet ministers suggesting that the UK would prosper on its own.
In general, over a quarter (28%) of likely voters think our EU membership is a good thing, 45% think it's a bad thing and 18% are neutral.
Voters aged between 18-34 are the only demographic group clearly in favour of the EU, with 44% calling EU membership a good thing and 25% a bad thing. The group aged between 35 and 54 are the mirror opposite (45% believe it is a bad thing and 26% a good thing).
Over 55's are much more clearly opposed, with 59% calling it a bad thing and 20% a good thing.
The poll also reveals that Labour's lead has fallen to seven points (from 39% to 32%).
The prime minister's net approval/disapproval rating has also jumped to the highest recorded by Opinium since April – -12% – although he is still behind Ed Miliband at -10%. Nick Clegg stands at -43%.
• Opinium Research carried out an online survey of 1,957 GB adults aged 18 and over from 13 to 15 November 2012. Results have been weighted to nationally representative criteria. Full polling results are available here
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