Lord Irvine will face direct questioning in the House of Lords today as to "whether the role of Lord Chancellor is compatible with that of a party fundraiser".
The Lord Chancellor's office confirmed he would answer the question, from Liberal Democrat Lord McNally, after the British government rejected demands for a statement on Lord Irvine's role in hosting a fundraising event for Labour-supporting lawyers earlier this month.
Conservatives sought to escalate the "cash-for-wigs" controversy, pressing Labour to reveal details of those who attended the fundraising event along with those who declined invitations, and the size of any donations made.
Despite attempts by Cabinet Office Minister Dr Mo Mowlam to exploit divisions in Tory ranks, the shadow lord chancellor, Lord Kingsland, urged Lord Irvine to "consider the position of barristers aspiring to take silk or to be appointed a judge", who had received his request to make a minimum contribution of £200 to help secure a second Labour term.
"On the one hand, some may feel they might incur disfavour if they did not donate; on the other, others might believe they may `catch your eye' by making such a donation," Lord Kingsland said in a letter sent to the Lord Chancellor.
Leading lawyers, academics and reformers, meanwhile, gave further momentum to proposals backed by the Law Society for reform of the Lord Chancellor's role as cabinet minister and head of the judiciary responsible for the appointment of judges and QCs.
Lord Lester, Liberal Democrat peer and leading human rights lawyer, said yesterday: "As the Book of Matthew teaches us, no man should serve two masters and Derry (Irvine) serves at least two masters, if not three or four. His politically naive decision may be important in highlighting the need to reform his domain."
Dr Mowlam claimed splits were emerging in Tory ranks after a BBC interview in which Lord Kingsland appeared to hold back from supporting party chairman Mr Michael Ancram's demand for Lord Irvine's head. And he defended the controversial Lord Chancellor's record of legal appointments, saying he had always acted with "absolute probity".
However, Lord Kingsland told the Today programme that, by allowing himself to be drawn into party politics and failing to reply to critics, Lord Irvine had forced the Conservatives to demand his resignation.
And Lord Kingsland later confirmed he, too, believed Lord Irvine should resign. Expressing his "concern" subsequently by letter, he called on Lord Irvine to publish details of those attending and declining to attend, in order to maintain the "probity" of present arrangements for the selection of judges and QCs, and to "ensure that anyone aware of political donations made by candidates for such appointments has no part in the appointments process, and is excluded from seeing files on applicants".
The latest ICM poll has indicated that cash-for-wigs-type controversies are having little impact on the voting public - with a 15-point Labour lead fuelling speculation that Mr Blair could opt for an April poll, and is still on target for a possible three-figure majority.