By politics.co.uk staff

The Conservatives are courting public sector workers by promising to set up cooperatives, in a renewed pitch to the left.

David Cameron used the launch of an advertising campaign aimed at core Labour supporters to announce the move in south London this lunchtime, saying it would "unleash a culture of enterprise and innovation".

Public sector workers would be allowed to form cooperatives under the Tory plans, described as a 'radical power shift to working people' by shadow chancellor George Osborne.

"Today we are announcing a bold and radical new reform which shows clearly how it is the modern Conservatives who have the plan that will help working people build a better life for themselves and their families," Mr Cameron said.

"You can be your own boss and offer the public a better service. The way you think it should be done, not the way a distant bureaucrat thinks it should be done."

The Tories have compared the measure to the right-to-buy reform of council house sales in the early 1980s. Under the measures not all of the savings made by the cooperative would be taken back by central government.

"It will unleash a new culture of public sector enterprise and innovation. Public sector workers will have a real stake in their success," Mr Cameron added.

"It has the potential to radically reform the way we do government. Put alongside our plans to protect frontline spending by scouring out waste and bureaucracy... it's a new and powerful reason for everyone in the public sector to vote Conservative, irrespective of how they have voted before."

The Unite union accused the Tory leader of masking right wing policy in left wing rhetoric.

Gail Cartmail, Unite assistant general scretary for the public sector said: "David Cameron is using the language of socialism to mask a break-up of public services. He is mangling the English language to advance his anti-state ideology."

The Tory leader unveiled a new poster campaign featuring three public sector workers explaining why they dropped Labour to support the Conservatives.

The last two Conservative posters - one of Mr Cameron's heavily photo-shopped face and the other of a grave mocking Gordon brown's 'death tax' have met an unfortunate reception, with many internet sites dedicated to humorous alternative versions of the original.

"The hopes you had with Labour that Britain would become a stronger, fairer society - those hopes didn't just die because Labour haven't achieved them.

"They're alive with us," Mr Cameron said on his WebCameron platform on YouTube.

A Conservative document called Two Nations yesterday accused Labour of failing the poor and saw Mr Cameron pledge to direct public cash to those who need it the most - a clear riposte to Mr Brown's attack that the Tory leader would govern for the rich.