The stage was set last night for a new clash between Lord Myners, the City Minister, and Sir Tom McKillop, the former chairman of Royal Bank of Scotland, after the Labour peer wrote to MPs spelling out what he knew about the award of a £16.9 million pension to the bank’s former chief executive.

The Timeshas learnt that Lord Myners sent a letter to the Treasury Select Committee yesterday clarifying what he knew about the decision to increase Sir Fred Goodwin’s pension pot by 50 per cent and when he knew it.

Sir Tom has also sent a letter to the committee requesting to return to the Commons to challenge Lord Myners’ version of events. The committee has decided not to recall Sir Tom but has invited him to make a written submission to them which the committee will make public. Sir Tom’s lawyers were drafting that letter last night, which will be delivered to MPs today.

Some members of the committee are anxious that it publish its report on the banking crisis soon and are worried that recalling executives to give new evidence will cause a delay. However, it is believed that several of the Conservative and Liberal Democrat MPs on the committee argued strongly that Sir Tom should be allowed to appear in person.

As The Times reported on Saturday, Sir Tom contacted John McFall, the committee’s chairman, last week, offering to provide fresh evidence after hearing Lord Myners’ testimony to MPs last Tuesday.

In his new evidence, Sir Tom is expected to spell out the conversations he and other RBS directors held with Lord Myners during the weekend of October 11-12 last year, when the Government was negotiating a rescue package for RBS. His evidence will include details of conversations held concerning Sir Fred’s pension.

This evidence has not before been aired publicly because when Sir Tom appeared before the committee in February, alongside Sir Fred and former executives of HBOS, the row over the size of the pension had yet to erupt.

Sir Tom is thought to be unhappy that, in his committee appearance last week, Lord Myners created an impression that he had not known how much Sir Fred’s pension was worth.

In a letter to The Times, published yesterday, Lord Myners pointed out that, in his introductory remarks to the committee, he had made clear that he had been told the size of the pension that weekend.

However, later in the same meeting, Lord Myners twice went on to suggest that he had not known about it.

Questioned by the Labour MP George Mudie, Lord Myners claimed to have contacted Bob Scott, the chairman of the RBS remuneration committee, setting out his objection to Sir Fred retaining certain share options.

Asked by Mr Mudie why he had not done this with the pension, Lord Myners replied: “Because the pension was not disclosed at that time . . . The pension was not disclosed until February.”

Later on in the session, questioned by the Conservative MP Andrew Tyrie, Lord Myners admitted that Mr Scott had told him Sir Fred’s pension would be “a large sum”. Asked by Mr Tyrie whether he had asked Mr Scott “roughly how much” Sir Fred’s pension would be, Lord Myners replied: “I did not, and Mr Scott offered no further information at that time.”

This version of events, it is understood, is contradicted by Sir Tom. He is expected to claim that Mr Scott held at least three conversations with Lord Myners during the course of the weekend on the subject of Sir Fred’s pension. In the last of these, it is said, Mr Scott told Lord Myners that Sir Fred’s pension was worth £16.9 million.

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