Liberal Democrat leader, Charles Kennedy, has predicted that the Tories could be pushed into third place forecasting a "significant realignment" in British politics.

As his party mounts a two-pronged attack on Tory tax cuts and Labour's election pledge card, Kennedy said the party could make considerable gains on June 7.

"Liberal Democrats will be fighting in every part of Britain to show that we can win. We have the potential to compete with Labour and push the Conservatives into third place," he said.

Speaking in Southampton as he travelled the country on a whistlestop tour he said that he had no policy on tactical voting arguing that individuals should make their own decisions.

On the BBC's Today programme, Lib Dem foreign affairs spokesman, Menzies Campbell, pledged that the party would fight every constituency and would continue to press Labour on proportional representation.

"The ambition is to get the largest number of Liberal Democrat MPs in the House of Commons that we can, to improve on the achievement of the last election, and to get the largest number of votes, because the case for proportional representation rests on the number of votes you get rather than the number of MPs," he said.

Promising that electoral reform was still on the agenda and describing progress towards PR as "inevitable" after devolution, he said: "There will be a reference to a fair voting system in Labour's manifesto. We must wait and see its exact terms."

"What if?" polling by MORI has shown that "if" voters believed that the Liberal Democrats could win in their seat 36 per cent would vote for them.

Kennedy is forecasting a realignment of the political system that has always placed the Tories either in opposition or as "the natural party of government".

In an exclusive interview with ePolitix.com he said that: "The potential is certainly there for a significant realignment of British politics, given a public which has a genuine sense of disappointment about quite a number of aspects of the government...there is also a sense of incredulity at William Hague's party."

Kennedy called for senior pro-EU Tories to join him and Labour in a joint cabinet committee.

"There's obviously the whole issue of Europe - I'd like a referendum sooner rather than later. Again that's something I think the two parties can usefully discuss - not just in fact our two parties but the pro-European Conservatives like Michael Heseltine and Chris Patten. I would be very happy to sit there in a tri-partite basis on European issues with other politicians from all parties," he told ePolitix.

Kennedy said he had "personal and professional respect" for Tony Blair stressing the "we've always got on well".

He said he enjoyed "an easy-going informal relationship based on mutual respect" with Blair but rejected claims that he was too closely aligned with Labour.

"That is the anti-pluralist approach to politics that inhabits certain sections of the Labour Party and doesn't like the fact that Tony Blair is willing to open his mind and his thoughts occasionally to leaders of other political parties," Kennedy said.