John Prescott yesterday said he was "satisfied" with the police inquiry into loans for peerages, amid reports that Downing Street has filed an unofficial complaint.
The deputy prime minister said Scotland Yard must be allowed to investigate any complaints, and "carry on with what they have to do in these circumstances".
His comments came after reports yesterday suggested Downing Street had complained to police that leaks to the media about the investigation were leading to them being portrayed unfairly - reports which are repeated in a number of newspapers today.
However, Mr Prescott dismissed the claims as "press prattle on a political agenda", telling BBC One's Politics Show: "Yes of course I am satisfied with it [the inquiry], as much as I know about it.
"I expect the police to carry on with what they have to do in these circumstances and I am sure it's exactly the same for every one of us. If you've got a complaint, as you have, you must investigate it to the full and, as I understand it, that's what they are doing."
Lord MacKenzie of Framwellgate, the former head of the Police Superintendents' Association and a Labour peer, told the Mail on Sunday that it would not be wise for Downing Street to try to intervene in the inquiry.
"The common ploy by criminals is to get their retaliation in first and make a complaint against the police to divert the attention of the authorities and put the heat on the police," he said.
"But it rarely works. If Downing Street is considering attempting to do this, they are making a catastrophic mistake. The police have to do their duty."
Last week it was confirmed that most ministers who served in the cabinet in the run-up to the general election had been asked by Scotland Yard by letter to provide written details of what they knew about secret loans to the Labour party.
Tony Blair was not among them, increasing speculation that he would be interviewed in person. It has been suggested police are waiting until he resigns, and asked yesterday if Mr Blair had been contacted, Downing Street said there had been "no change".
But further revelations yesterday continued to pile on the pressure on the prime minister, suggesting that Mr Blair misled Labour's governing body over who decided wealthy backers should give loans rather than donations to the party.
It was the revelation that millions of pounds in undeclared loans had been received by both Labour and the Conservatives, and that several of these donors had been nominated for peerages, that prompted the police inquiry.
In a memo published by the Sunday Times, a member of the National Executive Committee (NEC), Ann Black, recorded that Mr Blair had told the committee that contributors had wanted to give a loan rather than a donation as it was more discreet.
"Anyone giving to Labour was trashed in the media and so potential donors preferred the confidentiality of a loan, though he [Blair] did not explain why some donors claimed that the party proposed the arrangement, nor acknowledge that the lenders suffered far more through the facts emerging in this way," she wrote of the March 21st meeting.
However, two businessmen who gave loans and were subsequently nominated for a peerage, Chai Patel and Gulam Noon, have reportedly insisted it was not their idea to give a loan. Both their nominations were blocked by an independent commission.