Why mole leaked leaked MPs' expenses data

A mole leaked MPs' expenses details to the Daily Telegraph because he was angry about the Government’s failure to properly equip Britain’s armed forces while politicians spent millions of pounds of taxpayers’ money on themselves, the paper reports today.
The MPs' expenses mole tells his story in a new book, No Expenses Spared, telling the background to the MPs' expenses scandal which became the newspaper scoop of the year. The book reveals how the mole was among the workers who processed the MP's expenses files, and his colleagues included serving soldiers who were moonlighting to earn extra cash for body armour and other personal equipment.
The soldiers’ fury when they saw the way that MPs were lavishing taxpayers' money on their second homes led to the mole's decision to leak the data to the Daily Telegraph via a middleman. The man behind the leak - who is a civilian - says he has broken cover to tell his story for the first time, in the hope that it will shame the Government into supplying the right equipment for soldiers risking their lives in Afghanistan.
No Expenses Spared is written by two members of the Telegraph’s investigation team, Robert Winnett and Gordon Rayner. It describes the anger of employees at The Stationery Office – where the MPs’ files were sent for censorship before their intended publication by parliament – when they first saw the MP’s claims for second homes, furniture and luxury goods.
According to a report on the BBC, the Telegraph says it paid £110,000 for the story which is certain to win a string of journalism awards.