Conservative Party chairman Grant Shapps has insisted Ed Miliband's response over the Co-operative Bank row was "ludicrous" and stepped up pressure on Labour over the merger deal with Britannia.
Mr Shapps told the BBC's Sunday Politics there were "conflicting reports" about how much the Labour leadership knew about former Co-op Bank boss Paul Flowers' past, which included him standing down as a Labour councillor after pornography was found on his computer.
He said, "Arguing about what they knew and when, I think there's a much bigger issue here. This morning you have got Ed Miliband saying 'we don't have to answer any of these questions', they are somehow all smears. This is ludicrous".
Labour has denied this, saying Mr Miliband and shadow chancellor Ed Balls did not know the reason why Flowers quit in 2011.
Conservative chairman Grant Shapps has responded to Ed Miliband's claim that only Labour will fight for minimum wage earners amid a "crisis" in the cost of living.
Conservatives back the minimum wage. But if Ed Miliband was really on the side of hardworking people then he would have supported our welfare changes to ensure work always pays and should have voted in favour of halving the amount of income tax someone working full-time on the minimum wage pays.
Ed Miliband's policy is for more borrowing and more debt - the same old Labour policy that got us into a mess in the first place - and would mean higher taxes and higher bills for hardworking people.
The Conservative co-chairman, Grant Schapps, has cast doubt on reports in two newspapers that a senior Tory aide described party activists as "mad, swivel-eyed loons".
Asked who was behind the alleged comments, he told Channel 4:
Unfortunately I can't reveal the answer to that, simply because I was not there and as far as we are aware it was not even said, but we just don't know.
I don't believe anyone senior would say this type of thing, it's not an attitude or a view I have ever heard expressed in No 10, in Central Office. We respect and work with people who work incredibly hard as volunteers, unpaid, for the party.
I'm trying to make clear, I don't believe it's ever been said. You can always run a story that said there were 250 people in a room and one of them said this.
The trouble is with this story we don't know who is supposed to have said it.