The Liberal Democrats have called on Tony Blair and President Bush to soften their tone on terrorism.

In an exclusive interview with this website, the party's foreign affairs spokesman Menzies Campbell urged caution about the two men's responses to terrorism linked to Islamic fundamentalists.

His comments followed the joint conference by the two men strongly condemning the terrorist atrocities against British targets in Turkey.

"They obviously share very strong views about how we deal with the issue of terrorism. My anxiety is that there's too much evangelism in their approach," Campbell told ePolitix.com.

"I think the prime minister and the president, although neither of them used the word, nonetheless gave the impression of being on something of a crusade.

"It's a word that causes great offence in the Middle East. You have to be very careful about language in these things. Otherwise it's too easy for the supporters of terrorism to present these things as if it were a Christian West against a Muslim East."

The first state visit by a US president has been greeted by a major protest and been marked by a high security operation.

Campbell believes that with events still unfolding in Iraq, the visit could not have happened at a worse time.

"This visit was ill-timed, of that there is no doubt whatsoever. If circumstances in Iraq and elsewhere had been better the visit would have better," he said.

"In spite of the brave words I'm pretty clear that although in public President Bush and Mr Blair were entirely positive about the visit, both of them could have envisaged more favourable circumstances."

Asked if he thought the US president had been under siege, Campbell drew comparison with the visits by Bill Clinton to the UK.

"When President Clinton came to visit Britain, the problem was keeping the president away from the crowds. This time round the problem has been keeping the crowds away from the president," he said.

He doubted whether the visit had been of any real value to Blair.

"This visit was worthwhile to President Bush, he got the desirable news pictures of himself with the Queen and Mr Blair. But if you do a profit and loss account from the view of Number 10 Downing Street they would be hard pushed to say they were in the black."

Campbell, who met the president as part of the Liberal Democrat delegation, also described a president who is totally at odds to his media image.

"He's personally extremely engaging. He has a well-developed sense of humour, is self-deprecating and when he engages in a discussion with you he's warm and concentrates directly on you. He looks you straight in the eye and tells you exactly what he thinks," Campbell said.

"I wasn't persuaded by what he said but I was most certainly surprised at the extent to which the caricature of him was inaccurate."

He believed it was the only time during the visit that the president had actually encountered major criticism.

"I suspect we were the only group of politicians in Britain that he met who were challenging his political views. He'd met the Cabinet, Michael Howard and Michael Ancram. I think the Liberal Democrats proved to be a stimulating alternative," he said.