Firms are in discussion with HM Revenue and Customs, the Audit Commission, National Audit Office and the House of Commons about setting up random spot checks on MPs claims.

The talks follow a ruling by speaker Michael Martin to compel MPs to produce receipts for all claims of more than £25 and to bar politicians from receiving £3000 a year in 'petty cash'.

MPs in future will only be able to claim £50 a month, which must be strictly recorded.

The moves follow several scandals involving £80m in MPs expenses, the Telegraph reported.

A report from the Commons' Members Estimates Committee said: 'The new low threshold for claims needs to be underpinned by a more robust regime for audit.

'The committee is determined to establish audit controls which command public confidence.'