The Northern Ireland Office has denied a claim by a senior Sinn Fein source that Mr Peter Mandelson "ridiculed" the British Prime Minister during discussions between the Northern Secretary and Sinn Fein leaders.
Sinn Fein said last night that in talks with party leaders over recent months Mr Mandelson had been critical of Mr Tony Blair and his chief-of-staff, Mr Jonathan Powell.
"Peter Mandelson ridiculed Tony Blair and was highly critical of Mr Blair and Mr Powell over their handling of the Hills borough deal of May," said the Sinn Fein source.
The source refused to detail the nature of Mr Mandelson's alleged remarks. The fact that Sinn Fein has made this claim, about what presumably were private discussions, reflects the deterioration in the relationship between the party and Mr Mandelson.
An NIO source denied the claim. "It is not true. The British government operates with one voice on Northern Ireland. This is reminiscent of claims that Ulster Unionists similarly attempted to cause a rift between Mo Mowlam and Tony Blair by such allegations," he added.
Meanwhile, Mr Mandelson has pledged that the symbols of the new Police Service of Northern Ireland will be acceptable to nationalists and unionists.
He has insisted that the new title will be used for all "operational purposes" but has left it to the proposed Policing Board to agree new symbols for the cap and badge.
If the board cannot agree, Mr Mandelson will make his own proposals. This has raised SDLP and Sinn Fein suspicions that he may propose a symbol such as the crown which would be unacceptable to many nationalists.
But in an article yesterday in the Guardian, in which he defended his Police (Northern Ireland) Bill, due to be completed in the House of Commons on Tuesday, Mr Mandelson promised that neither nationalists nor unionists would be antagonised by the symbols which would be adopted.