By politics.co.uk staff
Attacks on Nick Clegg in Conservative-supporting newspapers appear to have had an effect.
The latest poll, published in the Sun today, with fieldwork conducted on Tuesday and yesterday, before last night's second leaders' debates, puts the Liberal Democrats back into third place.
Their rating of 28% is still eight points higher that it was for most of the first two weeks of this campaign and only a point behind Labour.
The Conservatives have opened a five point gap at 34%, but they would not gain enough seats to form a majority government if this poll was true for election day.
The state of the polls taken immediately after the debate confirms that the election is now a three-horse race.
Mr Clegg was narrowly behind Mr cameron in tow, but in three others he was deemed to
have won by 33% with the other leaders on 32%