David Cameron insisted Labour had "nothing new" to offer tonight as he delivered a scathing assessment of his opponents' manifesto.
Mr Cameron accused his opponents of relying on "scare" tactics, and promised the Tories would show they were "different" when they launch their own blueprint tomorrow.
Addressing a crowd in Loughborough, Leicestershire, Mr Cameron said the public was tired of the way politics had been conducted in Britain.
"They will have seen Labour's manifesto today and I can tell you, that is not going to change anything," he said.
"There is nothing new there, there is nothing different there."
He added: "We have got a great opportunity tomorrow when we launch our manifesto to show how we are going to be different and how we are going to make a difference."
Mr Cameron also made clear his fury that three Labour MPs charged with expenses abuses had been granted legal aid - insisting a Conservative government would ensure that did not happen again.
Mr Cameron said the General Election campaign had so far failed to engage millions of people.
"They hear the politicians shouting the odds at each other but they are not listening," he said.
"They want us to address the big questions, they want us to deal with the big issues.
"They know this country is in a deep hole and they want us to explain how we are really going to change things to get us out of that deep hole."
The Tory leader said Labour had failed to reform the NHS and education during 13 years in power.
He also lambasted his opponents' tactics, referring to allegations - which have been denied - that Labour targeted cancer patients with literature warning of cuts to the health service if Mr Cameron won.
"The other thing that is wrong with what Labour are doing is it is all about fear, it is all about frightening people. They are trying to frighten mothers by saying we are against Sure Start, but we back Sure Start and we want to expand it.
"They are trying to frighten old people by saying that we will take away bus passes or winter fuel payments.
"But I can tell you that we are going to keep those things.
"Labour have got to stop telling lies about what the Conservative Party will do.
"Just yesterday we saw, worst of all, they are trying to frighten people who are suffering from cancer.
"That is what happens with a Labour government. It starts with great hopes and great dreams, then there is the great disappointment, and it ends in the desperation of trying to frighten people who are desperately ill.
"The Prime Minister says he has got a moral compass. He should get it out and look at it, and make sure those leaflets are withdrawn."
Mr Cameron said his campaigning tour had reminded him of the "simmering anger" people still felt about the expenses scandal.
He said the Tories would "shake things up" by decentralising power and cutting the number of MPs by 10%.
Reacting to news that Labour MPs Jim Devine, David Chaytor and Elliot Morley had been granted legal aid to fund their defence against expenses abuse charges, Mr Cameron said: "What a complete outrage. What a complete outrage. The people who wouldn't even stand in the dock and answer the charges now expect all of you to pay for their defence.
"Well, I can tell you something - we are having a review of legal aid under a Conservative government. You can't preview and prejudice every part of that review but I can tell you what, there won't be legal aid available for MPs who are accused of fiddling their expenses."