The Labour leader told the BBC television Question Time programme that the party that had broken its promise on VAT on domestic fuel and heating bills, the party that had brought in poll tax was not the party to be trusted with people's pensions.
Mr Blair said that the Conservative had proposed a long-term move to private pension provision, but they had not explained how it would be funded.
"There is a huge hole in their explanation of where this money is to come from," he said. "And I can say to people very seriously; the choice of this election is between a Labour Party that will build on the state pension as we can, and a Conservative Party that is pledged to get rid of the state pension.
'Your pension will not be safe with them, and people understand that very clearly.
He told David Dimbleby: "Where is this money going to come from? They have never explained it. Pension provision is not safe with the Conservatives." To underline that point, Mr Blair then added: "A lot of people remember two things. One, a Conservative Party that before the last election pledged that they would not put VAT on fuel and then did it in the Budget straight after the election.
And the second thing people remember is the poll tax, which they said would be of enormous benefit to the people of this country and a mere administrative change in the financing of local government, and caused devastation.
"The party of the poll tax and VAT on fuel is not the party to be trusted with people's pensions."
In an earlier statement, John Major said that Mr Blair's statements on pensions were "scurrilous".
"They have made assertions that the Government has damaged the state retirement pensions," Mr Major said.
"Yet again, they know that charge to be utterly and totally without foundation at all. In plain terms, they are liars."
The Tories today take the attack on Mr Blair into the Labour leader's own backyard with an article he has written for Mr Blair's local paper, the Highbury and Islington Express in north London, challenging him to confront local Labour councillors who "fail" residents.
"Mr Blair says the true character of a party doesn't become clear until it's in power," Mr Major wrote. "In Islington Labour is in power and the 'character' of the party is clear: higher spending, higher taxes, poorer services, unabashed political correctness and repeated financial incompetence."
He urged Mr Blair: "Will you confront the teaching unions preventing the children of Islington from getting the education they are entitled to? Will you confront the Labour councillors who continue to fail you and your neighbours?
"Or will you get in your car, turn your back and drive away?"
The paper said it had offered Mr Blair, who lives in the Barnsbury ward of Islington, the chance to write his own article but he had declined.
One Tory source said of the attacks on Mr Blair: "There is a growing feeling that we are hitting home when we compare Steady John against Slippery Tony. We are appealing over the heads of the media and it is getting home to the people on the streets."Reuse content