David Cameron has been criticised by mental health campaigners after he branded Ed Miliband "nuts" for wanting to cancel a drop in corporation tax.
The prime minister first called the Labour leader "nuts" during an interview with the Sunday Telegraph but he chose to use the phrase again during an interview on the BBC's Andrew Marr programme this morning.
"Land Rover makes money around the world. Miliband want to put up their taxes. That's nuts," Cameron said.
"I'm going to get into a huge argument with the mental health lobby," he then added.
The comments comes a day after local government secretary Eric Pickles was criticised for telling a survivor of child abuse to "adjust your medication" during a debate.
It also comes after a week in which Tesco and Asda removed a 'mental patient Halloween outfit' from the shelves following an online outcry.
"The prime minister had the opportunity to change his choice of language in his interview with Andrew Marr, but continued to use the word 'nuts'," Rethink Mental Illness communications director Jane Hughes told Politics.co.uk.
"It's disappointing that he doesn't see why this kind of language is insulting to people with mental health problems, particularly as it comes so soon after Eric Pickles told someone to 'adjust your medication'.
"The row over the Asda Halloween costume this week shows that there are far more blatant examples of stigma against mental illness than this, but lazy and insensitive language is often the first step towards bigger problems.
"Many people with mental health problems tell us they find the stigma surrounding mental illness worse than the condition itself."
Cameron used the Marr interview at the start of the Conservative party conference to criticise Miliband's plans for a two-year energy price freeze.
"The problem with what Ed said [on energy prices] was it unravelled in 24 hours when he said the next day he might not be able to keep his own promise," he said.
"Take his approach as a whole – it's anti-business, it's anti-enterprise. It's saying to companies in Britain: 'I'm going to raise your taxes, drive you out'.
"We've got to build this recovery. We need to get business to invest.
"Bashing and taxing business is going to cost us jobs, set us back and make our recovery weaker. That is wrong."
Miliband has enjoyed a sizeable eight-point boost to his personal poll ratings since he made the energy price pledge, while Labour has won an 11-point lead in the polls.
The prime minister insisted that after facing a variety of Labour and Liberal Democrat leaders he was always careful when sizing up a political opponent.
"You never underestimate anyone in politics," he said.
"Politics ought to be competitive. It keeps us on our toes."
Cameron is presiding over a conference in which he must try to deal with the Ukip threat to his right while addressing Labour's push on the 'cost of living crisis' on his left.
"This next election is wide open to win," he said.
"We have a huge battle. We have to persuade people that went to Ukip to come back.
"We have to persuade Labour voters that it's an anti-enterprise party – come over to us at the Conservatives.
"I'm passionate about a Conservative-only government. The country needs us to go further and faster on the things that really matter."
Delegates are arriving today for the Tory conference in Manchester. It begins with a tribute to Margaret Thatcher and will end with a keynote speech by Cameron.