By Ollie Stone-Lee
BBC News, political reporter, Labour conference in Manchester
Labour risks making the same mistakes in taking on David Cameron as the Conservatives did in Tony Blair's early days, says minister Margaret Hodge.
Labour is pondering how to deal with Mr Cameron
Mrs Hodge said the Tories in the 1990s had veered from painting Mr Blair as "Bambi" and then as a "control freak".
She told Labour delegates that adverts showing the "new and fresh" Mr Cameron as a chameleon had not worked.
Former adviser to Gordon Brown Ian Austin said it was vital nobody got the idea New Labour ended with Tony Blair.
'People like him'
Mr Cameron's Conservatives have overtaken Labour consistently in recent opinion polls. The Progress fringe meeting debated whether Labour was tackling the Tory leader's threat in the right way.
Industry Minister Mrs Hodge said that for the first time in 12 years the Tory Party was a credible opposition which must be taken seriously.
Mr Cameron might not yet have made a serious breakthrough but he probably had three years to go before the next election, she said.
"We may think here in the Labour Party that he's a traditional public school toff... but people do like him," she said.
Mrs Hodge said Labour needed to decide quickly what its strategy for attacking Mr Cameron would be.
Labour lampooned the Tory leader in the local election campaign with cartoon character "Dave The Chameleon".
But Mrs Hodge said: "I don't think showing him as a chameleon was the right way to go ahead.
"Mondeo Man and Worcester Woman did not understand what we thought he was about."
She said the message had been too sophisticated for voters in her Barking constituency.
"We need to remember the mistake the Tories made in their attacks on Tony Blair - first branding him as Bambi and then as a demonised control freak," she argued.
"The time lost floundering around agreeing a strategy cost them dear."
Mrs Hodge also said talk of reform was difficult for Labour.
Staff in the NHS and education were the best ambassadors for public services and their support must not be weakened, she said.
"If we continually bang on about reform, I think we lose them as our ambassadors," she said.
Mrs Hodge suggested "improvement" was a better word to use.
Mr Austin, who is now a Labour MP, said the party must show reforms would continue.
He warned against the claim that the New Labour project was at risk once Tony Blair left and there would be no more modernising government.
"The surest way to us losing the next election is some suggestion that reform stops as soon as Tony Blair goes," he said.
His words will be seen as a warning against any supporters of Mr Blair who want to paint Mr Brown as an old-style figure.
'Character, not celebrity'
Mr Austin said Mr Cameron had done a good PR job in trying to reposition his party but had not really changed the party.
"Vague claims about intent are not enough," he said.
He accused Mr Cameron of hypocrisy by plugging his green credentials while opposing Labour's climate change levy.
"The issue is not personality and celebrity, the issue is policy and character," said Mr Austin.
Health Minister Andy Burnham said Labour should not fall into the trap of over-obsessing and talking about Mr Cameron too much.
Labour had to get better at "peeling away" Mr Cameron from "hard-core Thatcherites" in his party, added Mr Burnham.