Arrest of Damian Green by counter-terrorism police is an outrage

The arrest of a shadow cabinet minister under anti-terrorism powers can only have taken place with sanction from the highest level. And, if the Daily Telegraph is correct, then it is clear that Green's offence is embarrassing the government:

It is understood that the inquiry is focusing on four Home Office documents allegedly obtained by the Conservatives. Last November, documents from the private office of Jacqui Smith, the Home Secretary, were leaked to the opposition.

They showed that ministers had known for four months that thousands of illegal immigrants had been cleared to work as security guards but had not told Parliament.
Other documents included information about an illegal immigrant working at House of Commons and a list of Labour MPs preparing to vote against the Government's anti-terrorism measures.

Moreover, by acting in this way the government will only strengthen the public perception that it has something to hide on immigration. You would have to be quite extraordinarily stupid to think anthing else. In fact, it hard to think of anyone who who could be so mind-numbingly stupid as to approve this action.

Hello, my name is Jacqui Smith.