A man has been arrested by armed police near an entrance to the Houses of Parliament.

About a dozen officers swarmed around the suspect as he was held against a fence inside the Carriage Gates on Tuesday.

The entrance was the scene of a terrorist atrocity in March 2017 when Khalid Masood murdered unarmed police officer Keith Palmer.

At the time there was shock at the lack of an armed presence near the gate, and chief coroner Mark Lucraft QC found shortcomings in security at the site meant marksmen did not know where they were supposed to patrol.

Since the attack, security at the site has been beefed up, with a permanent armed presence at the entrance.

The man was taken away in a police car shortly after 12.15pm.

The incident, during which the suspect was Tasered, is not believed to be terror-related.

A Metropolitan Police spokesman said: “A man was detained and arrested by Carriage Gates, inside the Palace of Westminster, on suspicion of trespassing at a protected site, at around 11.55am on Tuesday December 11.

“A Taser was deployed. Inquiries into the circumstances continue.”