MPs on the Commons standards and privileges committee are reported to be "running around like headless chickens" over the findings of a report into Iain Duncan Smith's use of parliamentary allowances.

The report, by parliamentary standards commissioner Sir Philip Mawer, is said to clear the former Conservative leader of any wrongdoing in the employment of his wife Betsy as diary secretary.

However, MPs are thought to be concerned about the possible implications for how the spending of allowances are accounted for in the future.

At least 50 other MPs are thought to employ family members in their Westminster offices.