A secret terror attack drill in Parliament has exposed shocking security weaknesses, it has been revealed.
Police posed as terrorists in a mock attack on the Palace of Westminster in a dramatic night-time operation earlier this year during recess, the Sunday Telegraph reported.
Officers pretending to be attackers used a boat and travelled along the Thames to access Parliament via one of its riverside buildings.
According to the newspaper, three separate sources gave accounts of what had happened and said the ease with which the police were able to access Parliament showed MPs were “sitting ducks”.
A spokesman for the Houses of Parliament authorities would not confirm or deny that the operation had taken place.
The officers were reported to have stormed into the Commons chamber within five minutes in a way which could have led to a “massacre” if the House had been sitting.
A review of security at the House of Commons is under way following the Westminster terror attack in March which killed a police officer guarding the palace’s front gates.
The Telegraph said the review had highlighted the need for a barrier in the river to stop boats approaching Parliament, as well as an armed guard to protect entrances from the Thames.
A spokesman for the Houses of Parliament said: “The security of members, staff and the visiting public is our highest priority.
“While we cannot comment on the specifics of our security, we work closely with the police, security services and others to ensure that our security measures are effective and meet whatever level of security risk Parliament faces.
“These measures are always, and will continue to be, under constant review.”