Ed Balls and Yvette Cooper are facing an inquiry by the parliamentary standards watchdog after Tory MP Andrew Bridgen wrote to the organisation demanding an investigation of the £14,000 the couple have claimed in travel expenses for their three children.

In his letter Bridgen wrote: “I believe that how Ed Balls and Yvette Cooper have acted in claiming more than a normal family would claim for is in contravention of the spirit of the rules.

“While it is right that the House recognises the different circumstances of husband and wife members, there should be no distinction between the rights given to families where both parents are members and families where only one parent is a member.”

Barnsley Central by-election, following expenses fraud

An MP has the right to claim upto 30 travel expenses per child a year, and since both Ed Balls and Yvette Cooper are MPs they can together claim for twice as many free trips as other families, where only one of the parents is an MP.

Shadow Education Minister for Children, Sharon Hodgson, said: “This is a desperate new low from the Tories to try to drag their children into a political fight.

“Ed and Yvette have to be in Parliament and their constituencies each week and they also take their family responsibilities very seriously.

“Who on earth does Mr Bridgen think is supposed to look after their children if they have to leave them behind in London or Yorkshire? He isn’t living in the real world.

“This is yet another bogus and politically-motivated complaint.”

Labours’ Shadow Chancellor Ed Balls, and his wife, the Shadow Home Secretary Yvette Cooper, have claimed expenses for 375 journeys for their three children’s travel between 2007 and 2010.