The prime minister has repeated his claim that he can win the forthcoming referendum on the European constitution.

Speaking during a question and answer session alongside Jacques Chirac in France, Tony Blair said he wanted to tackle the "politics of fear".

"You need to explain this is not something people should fear but which is progress," he told British and French students.

"The argument we have to make to people within Britain is that if we want to continue with the peace and prosperity we have enjoyed, our place is in Europe."

But he conceded that the government was facing a powerful coalition ahead of the poll.

"We should never underestimate the strength of this politics based on fear," said Blair.

"This politics of fear is always very powerful. It is the one part of politics that I know and any democratic politician knows has the ability to spark something very dangerous."

Ahead of a working lunch with Blair, the French president put to one side cross-channel disagreement over the merits of holding a national poll.

Chirac said he could not "conceive of Europe without Britain".

And he predicted that the government would win the referendum. "Tony Blair is very convincing, he will sway public opinion," he said.

Both leaders later headed for a working lunch with French prime minister Jean Pierre Raffarin where they were expected to discuss the remaining obstacles to agreement on the referendum treaty.

Tory splits

The prime minister's comments on the constitution came amid evidence of Tory splits over Michael Howard's Euroepan policy.

Speaking on Sunday, former foreign secretary Lord Howe said the Conservatives should support the constitution in the forthcoming referendum.

“I’m dismayed that we haven’t really been able to address the way ahead. It should be an exciting moment – the expansion of Europe between literally all the Soviet Empire," he said.

"If we want to play a positive and constructive role in that Union, we need to sound as though we want to and not be dismissing it as something that we’d rather not touch with a barge pole.

“He [Howard] said he was determined to maintain a constructive and positive role for Britain in the European Union.

"Now, how he reconciles that with the outcome of the referendum, and the outcome of the election campaign, is of great importance."