A PEER in the House of Lords is threatening to report Bolton West MP Ruth Kelly to the parliamentary ombudsman in a row over questions about so called "fat cat" pensions.

Lord Oakeshott, Liberal Democrats pensions spokesman in the House of Lords, believes the financial secretary to the Treasury has got her figures wrong when estimating the number of people with large pensions who are facing a possible tax increase.

However, a spokesman for the Treasury said Lord Oakeshott's threat was "pointless" as Ms Kelly would not break parliamentary rules by failing to respond to his question by tomorrow's deadline.

Lord Oakeshott has dismissed as "pure nonsense" her claim that only 5,000 people would be hit by a proposed 33 per cent tax on pension surpluses above the lifetime limit of £1.4 million.

Though the Government maintains that its proposed levy -- which will mean that some people end up paying nearly 60 per cent tax on their pensions -- will hit only the richest few, critics claim that the net will be much wider.

Lord Oakeshott, who believes it could affect up to 100,000 people, has asked Ms Kelly for the latest figures for the number of people who retire on pensions of £50,000 and above.

But the Government spokesman said: "We have published a figure of 5,000 people that will be affected and we will stand by this figure."