Yorkshire fighting talk for Clegg and Cameron

Picking up where they had left off the previous night at the final leaders' TV debate, the Liberal Democrat and Tory leaders launched blistering attacks on one another's policies – leaving Labour looking almost side-lined by comparison.

Mr Clegg received a warm welcome from supporters when he arrived at Sheffield's Crucible Theatre yesterday afternoon, but was less well received by some of the snooker fans inside.

While Mr Cameron was meeting voters just 15 miles up the road in Penistone, Mr Clegg addressed the audience at the afternoon session of the World Snooker Championships – some of whom greeted him with jeers.

But after a short speech, including the obligatory reference to Gordon Brown's "bigot-gate" gaffe earlier in the week, Mr Clegg left the crowd to the game, saying: "I know you're here for snooker, not politics".

Outside, the Sheffield Hallam MP told the Yorkshire Post he was proud of the Liberal Democrat council's achievements in Sheffield, a city which had once been "synonymous" with Labour.

"It's certainly no longer true that urban Britain is Labour Britain," Mr Clegg said.

"Urban Britain is increasingly becoming Liberal Democrat Britain, much as here in Sheffield.

"There are also what once were very traditionally Conservative seats that are already held by the Liberal Democrats, like Harrogate, and places like Bradford where I think we now stand a very strong chance indeed to win against Labour.

"In a lot of those areas people feel very let down by Labour, they don't want to be let down a fourth time, and they are looking for a fresh alternative – and they are finding that in the Liberal Democrats."

Having earlier described the election as "increasingly a two-horse race" between his party and the Tories, the Liberal Democrat leader launched a blistering attack on Mr Cameron – describing his claims to offer a change in British politics as "fake" and "plastic".

Mr Clegg said: "I think David Cameron really needs to be tested by what on earth he means by change. What would really change? Nothing would change in the banking system – the Conservative party have been in the pocket of the City of London for generations.

"Nothing will change in the school system because he wants to cut funding, and nothing will change in the environment because he has clubbed together in Europe with people who say climate change doesn't exist.

"This is one of the biggest false claims to change in British politics I can ever remember – it's plastic and it's fake."

But up the road in the picturesque village of Hoylandswaine, in the Penistone and Stocksbridge constituency, Mr Cameron was firing his own salvos at the Liberal Democrat leader.

Speaking after a meet-the-voters event in the local village hall, Mr Cameron admitted the televised debates had "opened it up" for Mr Clegg but said his talk of a two-horse race was "rather wishful thinking". He said: "It was challenging for us, but I think we've come back strongly – I think the Conservatives are making the big arguments now. We're now in the final week of the campaign and I think we've got the momentum."

Attacking the Liberal Democrats for their policies on immigration and Europe, Mr Cameron said they offered "muddle and uncertainty" and again warned against the prospect of a hung Parliament.

"If you want a new Government on Friday, then you must vote Conservative on Thursday," he said.

South Yorkshire has not elected a Tory MP in almost 20 years, but Mr Cameron believes they have a chance of victory in the new Penistone and Stocksbridge constituency, where Labour holds a notional majority of around 8,000.

He said: "There are no no-go areas."

n The Guardian newspaper today came out in support of the Liberal Democrats, after many years of backing Labour. But its editorial made clear that it had "reservations" about the party, warning that they remain largely a party of the middle and lower-middle classes and have failed to promote female and ethnic minority candidates for Parliament.

The Conservative campaign gained a boost when David Cameron's party won the endorsement of The Times – the first time since 1992 that the paper has backed the Conservatives in a General Election.

Apology over use of word 'nutters' in TV debate

Nick Clegg has apologised for describing allies of David Cameron as "nutters" during one of the prime ministerial debates.

The Lib Dem leader responded to complaints from mental health campaigners by saying he was sorry for using the "derogatory" term.

The remark was made in the second debate, broadcast on Sky News on April 15. Mr Clegg said that the Tory leader had aligned himself in Europe with "nutters, anti-Semites, people who deny climate change exists and homophobes".

Responding to a complaint from the charity Stand to Reason he wrote to director Jonathan Naess: "You have raised concern about my use of the term 'nutters' in the debate and I am sorry for any offence caused.

"I am acutely aware that the stigma of mental health causes great distress to many people and my use of language that could be considered derogatory was entirely unintentional."

In his letter, sent yesterday, Mr Clegg insisted he had "consistently tried to raise the profile of mental health issues and will continue to do so".

He stressed that the Lib Dem manifesto included a "strong commitment" to improving support in the area. "I believe that parliamentarians have a responsibility to help change attitudes to mental ill health and I will ensure that my belief in this principle is represented in the language that I use in future," he added.