Stephen Byers bags £125,000 for his partner's flat through MPs' expenses

In the past five years Mr Byers, a close ally of Tony Blair, the former prime minister, has spent £27,000 of taxpayers' money on redecoration, maintenance and appliances at the basement flat in Camden, north London, which he shares with Jan Cookson.

This included more than £12,000 towards extensive renovations to the exterior of the entire building, which contains four flats, in 2007.

Mr Byers becomes the second MP found by the Telegraph investigation to have used their expenses to benefit their partner.

Ben Bradshaw, a junior health minister, used his to pay the full mortgage interest on a house in London that he shares with Neal Dalgleish, his civil partner.

The flat in Camden was bought in November 1982 by Miss Cookson, Mr Byers's partner of 22 years. It is unclear how much she paid for it. In 2001 the flat two floors above sold for £170,000.

The pair also share a semi-detached house worth about £400,000 in Mr Byers's North Tyneside constituency, which they bought together in 1996. Mr Byers owns a third property, also in Newcastle, which he rents out.

Miss Cookson, a lawyer, does not have a mortgage on the London flat, meaning that Mr Byers cannot claim interest charges on monthly loan repayments, as many MPs do on their second homes. Mr Byers, who served as trade secretary and transport secretary under Mr Blair, confirmed to The Sunday Telegraph that he does not pay rent to Miss Cookson for living in the flat while in London on parliamentary business.

Yet between 2001 and 2008 he claimed a total of £126,648 in expenses for the property.

Documents filed to the Commons authorities show that Mr Byers charged the entire £12,033 bill for Miss Cookson's share of renovations made to the outside of the building between February and November 2007.

The fee covered unspecified decorations as well as brick cleaning, roof repairs, paving and drain cleaning.

Between 2004 and 2005, Mr Byers also charged £4,867 for general repairs, maintenance, insurance and security for the flat. In the same year he claimed £530 for the repair and repainting of hallway doors, walls and ceilings, and £388 for a Bosch washing machine from John Lewis on Oxford Street.

Between 2005 and 2006 he spent £3,384 on the upkeep of the flat. He also claimed £980 for repairing a collapsed wall, £390 for repairing the flat's gas boiler and £175 for repairing a broken window.

He also spent £237.50 on decorating and £240.50 on the replacement of bathroom tiles. At the time MPs did not need to submit receipts for purchases under £250.

The following year, in addition to £3,366 he spent on general maintenance, he claimed for another £577.50 on plumbing and boiler work, and £236 on having the flat's kitchen repainted.

Mr Byers, 56, is remembered for his decision in 2001 to put Railtrack, the privatised railway company, into administration and create Network Rail. The move prompted about 48,000 shareholders to take the Government to the High Court in pursuit of £157 million in compensation.

The claim was rejected and Mr Byers was cleared of all wrongdoing in Oct 2005.

In 2002 Mr Byers, who has a son in his thirties from a previous relationship, admitted being unfaithful to Miss Cookson.

In the past five years he has topped up his £64,766 MP's salary with regular speaking appearances and national newspaper articles for which he earned up to £5,000 a time.

He works as the non-executive chairman of both a Skipton-based water treatment company and a company that promotes links between Ukraine and the EU, and is a consultant to an Athens-based construction company.

Mr Byers's expenses claims show that he regularly claimed the maximum £400 per month for groceries – including when Parliament was in recess.

Mr Byers told The Sunday Telegraph: "All of the expenses I have received are within the rules and have been approved by the House of Commons authorities."