What the allowance covers

Some have used it to pay for hi-fis, TVs, paintings and kitchen appliances in second homes.

It was created to meet "necessary costs incurred when staying overnight away from their main home for the purpose of performing parliamentary duties."

An attempt to curb the claims made by London MPs was thrown out by the Commons last summer.

The independent Senior Salaries Review Body questioned why outer London MPs should pocket the allowance, saying some should catch the train home at night.

It urged a review to decide which MPs in outer London constituencies should be able to collect the money. But a proposal to cut the amount by £10,000 was voted down.

The allowance was introduced to help MPs from outside London pay for a hotel room or flat in the capital.

Outer London MPs qualified because of the inconvenience of late-night sittings. Before 2001 when "family-friendly" hours were introduced, the Commons often sat past midnight.

But now the Commons only holds late votes on Mondays and Tuesdays, and MPs can get away in the early evening on most days.

Most keep Fridays clear for constituency business and some work a truncated Westminster week, arriving on Monday afternoon, and leaving Thursday afternoon.

Some members admit they use the second home allowance to fund a bolt-hole that is neither in London nor their constituency.

One is reputed to pay for a holiday home with money from the taxpayer.