By Mark Davies BBC News Online political reporter in Bournemouth

The former Tory chairman says Iain Duncan Smith will regret allowing Theresa May to describe their party as having had a "nasty" image.

I think this nice and nasty is really irrelevant

Lord Tebbit

Labour MPs will be eagerly awaiting the return of the Commons in order to "constantly tell Conservatives they're nasty and that even their own party calls them nasty," Lord Tebbit says.

And it isn't difficult to imagine Labour speechwriters preparing to make hay with the comment.

The speech on Monday by party chairman Mrs May stunned many Tories and has been the talk of coffee bars and fringe meetings in Bournemouth.

Astonishment

It has also done wonders for Mrs May's image. Her fondness for colourful shoes aside, the former transport spokesman was regarded by many as a poor performer before Monday.

Tebbit: Tories 'not nasty'

Indeed, there was a certain amount of astonishment when she became party chairman.

Yet this week, some have spoken of her as future leadership material. That may be well off the mark, but her speech was certainly one of the highlights of conference season.

But will it come back to haunt the Tory leadership?

Lord Tebbit thinks so. "I think this nice and nasty is really irrelevant," he said.

Trouble

"I don't think it's going to make it very much easier for Iain Duncan Smith to dominate the House of Commons."

I think at various moments we may be mistaken very slightly with sounding as if we are demonising, which is a completely different position

Oliver Letwin

Lord Tebbit said any nastiness in the party "was among the group of people who pulled down Margaret Thatcher and left the party utterly rudderless for some time".

If the party was so nasty, he asked, why did so many people vote for it in 1979, 1983 and 1987?

He added: "The party got into trouble not because it was nasty but because it was incompetent, economically incompetent." Difficult

On Thursday, though, Mrs May was unrepentant.

"There was a perception out there that the party was a nasty party, that we weren't caring, and I think what we need to do as a party, and have needed to do, is actually face up to that fact," she told the BBC Radio 4 Today programme.

"Some people might find the language I use difficult but I think it's important for us to be honest with ourselves, because unless we're honest with ourselves about how voters see us then we're not going to be able to address that and present the right policies to the electorate and actually move forward."

And she said it was time for the likes of Lord Tebbit to move on.

She added: "Obviously within the party there will be those who take a different view to that that I've expressed, and there will be those who wish to express their views on that.

"I think for those who want to carry on living in the past the party has to move on and move forward."

'Demonised'

What the episode highlights is the dangers of language in the political world.

Letwin: Softer than Blunkett?

Shadow home secretary Oliver Letwin, for instance, distanced himself from Mrs May's suggestion that the party had "demonised" minorities in the past.

He said the party may have sounded that way at times, but that it was never actually the case.

"I don't think we have ever had the inclination to demonise minorities or anybody else," he said.

"I think at various moments we may be mistaken very slightly with sounding as if we are demonising, which is a completely different position."

Failure

Mr Letwin's opposite number, David Blunkett, knows all about the dangers of using strong language.

There are dyed in the wool Tories who read the Daily Mail and feel that David Blunkett's rhetoric is right and that mine is too weak and wrong

Oliver Letwin

His comment about the children of asylum seekers "swamping" schools will not be quickly forgotten.

And at Labour's conference last week, he bemoaned what he said was the failure of some to read beyond the headlines and analyse his policy in detail.

The home secretary's reputation as a hard man, of course, is a Godsend for Mr Letwin, the leading exponent of "compassionate Conservatism" as the Tories try to transform their image.

And he has sought to highlight the differences between him and Mr Blunkett.

Annihilated

At a fringe meeting Mr Letwin said he was "softer" and "weaker" on immigration and asylum than Mr Blunkett.

He said the Conservatives used the "strongest language on asylum for a generation" at the last general election and were annihilated at the polls.

"There are dyed in the wool Tories who read the Daily Mail and feel that David Blunkett's rhetoric is right and that mine is too weak and wrong.

"I wonder what those people will feel three years from now when there is no improvement.

"I think they will prefer something that is softer and more effective in practice."

Nice, nasty. Hard, soft. These are interesting times in the political world.