The Pontefract and Castleford MP and her husband, the MP for Normanton, were investigated by the independent parliamentary commissioner for standards following a complaint in February about their use of second home allowances.

Conservative MP Malcolm Moss had queried whether the ministers' London property was in fact their second home, rather than their other house in Castleford.

The commissioner's report, published on Wednesday, said: "Overall my conclusion is that Ms Cooper and Mr Balls made reasonable decisions on the basis of their own circumstances in declaring their property in Castleford to be their main home.

"I conclude that that decision was fully in accordance with both the letter and the spirit of the rules of the house. I therefore dismiss this complaint."

The Additional Costs Allowance, under which the couple claimed for their London residence, allows each MP to claim up to £22,000 a year each on top of their annual wages but the money is not to be used for MPs' primary residences.

The report added that there was no evidence the couple identified their Castleford property as their main home to maximise benefits and they sought advice on the matter.

Ms Cooper said: "I'm very pleased the commissioner has thrown out this politically motivated complaint and confirmed we have acted completely within the spirit and the letter of the rules.

"MPs have to be in Parliament and back in their constituencies each week to do the job.

"As a mum with young children I think it's important our family stays together, and that means we have to travel hundreds of miles each week so we can come back home to Castleford when Parliament isn't sitting. I've argued strongly for MPs to be subject to more independent checks."

l To see the full report visit http://www.publications.parliament.uk/pa/cm/cmstnprv.htm#reports.