Two West Midlands Conservative MPs have been asked to pay back more expenses after Sir Thomas Legg's audit of past claims.

Shadow international development secretary Andrew Mitchell, the MP for Sutton Coldfield, faced a demand for £2,673.33 he claimed towards council tax and mortgage interest.

Meriden MP Caroline Spelman, the shadow communities secretary, was asked for £2,167.51 in cleaning, utilities and telephone bills.

The amounts were requested in Sir Thomas's final round of demand letters sent to MPs earlier this week. They are in addition to earlier demands by Sir Thomas and voluntary repayments made independently of his audit process.

Meanwhile, minister Sion Simon, MP for Birmingham Erdington, has agreed to pay back about £21,000 he claimed in expenses to cover rent that he paid to his sister.

The Minister for Creative Industries, apologised "unreservedly" as he admitted he should not have been claiming the cash because it was against the rules. But he insisted he had not been aware that the claims were not allowed and offered to pay back only the amount he drew down after the rules were made explicit in 2006.

He is thought to have claimed about £44,000 between 2004 and 2008 towards rent that he paid to his sister, Ceri Erskine, for the use of her flat near Regent's Park, north London.

The Labour MP for Birmingham Erdington said he obtained approval from the House authorities before renting the property. The rent was £1,000 a month, which he claimed back under the Commons second home allowance until he moved out at the end of 2007.