Bracknell MP Andrew MacKay found himself at the heart of a political scandal when he walked into the middle of an arrest in Parliament.

Tory Mr MacKay waded as anti-terror police raided MP Damian Green’s parliamentary office – an act he says started a civil war the last time it happened.

Mr MacKay, who is political adviser to Conservative leader David Cameron, was captured on video as he stepped into Mr Green’s office last Thursday to ask police what they were doing.

He said this week: “I was having a quiet snack in the members’ tea room and I got a call to go to David Cameron’s office.

“He had just been informed they were going to raid Damian Green’s office. We were appalled and decided to take action.

“We are extremely cross because an MP’s office was wrongly raided.

“Let us not muddy the waters – MPs are not above the law and nor should they be but this is an issue of parliamentary privilege and the only information he received was of a totally non-secure nature and was all in the public interest.”

Mr MacKay pointed out the last time an MP was arrested for carrying out his parliamentary work was in 1642, during the reign of Charles I and it led to a civil war.

Damian Green was arrested at his home in Kent in relation to a leak of sensitive Home Office information.

His home and office were searched, his laptop, computer and mobile phone were all seized, as were personal documents including bank statements and 20-year-old love letters to his wife.

Mr Green was released without charge.

The investigation continues.