The Conservatives have enlisted the example of former prime minister Sir John Major to claim that they are the real "workers' party".
Tory chairman Grant Shapps said that Sir John's life story - rising from his working class roots in Brixton to occupy No 10 Downing Street - made him a "symbol of our party".
In a speech to activists at Conservative headquarters in London, Mr Shapps said the current Government was committed to building the "classless society" which Sir John campaigned for when he was in office in the 1990s.
"His life is a symbol of our party. It shows whose side we are on. As David Cameron has said many times: W e are not here to defend privilege, w e are here to spread it," he said.
He said that the party had to demonstrate that it was on the side of ordinary working people.
"That's the message we have to get across to people - t he Conservatives are the workers' party and we are on your side," he said.
Mr Shapps said the politics of the Conservatives were not just about austerity and cuts but had a "moral purpose".
"Sir John Major campaigned for what he called a 'classless society' a nd I would argue that this Government is fighting to secure that kind of society today - a Britain where it doesn't matter who your parents are, w here you can go as far as your talents and hard work will take you a nd where work - rather than benefits -is what pays," he said.
The decision to highlight Sir John's example will be seen as an attempt by the Conservatives to counter accusations that under Mr Cameron the party is dominated by privileged ex-public schoolboys who do not understand the concerns of ordinary people.
For Labour, shadow cabinet office minister Jonathan Ashworth dismissed the Conservative claim to be the workers' party.
"You can't pose as the 'workers' party' when you've made working people £1,600 worse off while cutting taxes for the wealthiest. Under David Cameron, for the first time more than half of households in poverty are in work. He has made his choice: Standing up for a privileged few, not for working families," he said.
"Labour has always been the workers' party - the clue is in the name. Asking John Major for help is just a reminder that he was the last Tory leader to win an election - and that Tory MPs don't believe they can win under David Cameron.
"With David Cameron's record as leader they'd be better off renaming themselves the millionaires' party."
Journalists were not admitted to the event, but according to extracts released afterwards by Conservative Campaign HQ, Sir John used his speech to attack Labour as the "party of class warfare".
"We Conservatives want people to help themselves. To make their own opportunities. To create something better for themselves, for their families, for their community and for their country. I don't believe that the Labour Party can do that," he said.
"The Labour Party is the party of class warfare and class division. They set people against people, rich against poor, north against south, haves against have nots. If it's for their political convenience they will sow division not unity. That is the way they have operated since their foundation."