MPs Stephen McPartland, Sir Oliver Heald, Alistair Burt and Heidi Allen ‘hunkered down in meeting rooms’ amid lockdown after shooting at Houses of Parliament

Stevenage MP Stephen McPartland tweeted: “Heard gunfire but safe inside Parliament now. Saw brave police officers and security pulling public inside to safety.”

Speaking to this newspaper from parliament, he added: “We are all in different sections of the building as we were about to vote. I saw them pull at least 20 to 30 people inside near the door I was using and lock it down.

“Lots of armed police are running towards the incident.”

Proceedings in the House of Commons have been suspended amid the attack, during which two people are thought to have been injured, with one reported to be a police officer.

Sir Oliver Heald, MP for North East Herts, told us directly: “We’re hunkered down in meeting rooms. The position is still uncertain at the moment.

“It’s obviously very worrying but the speaker is investigating with the security people to figure out what’s going on.”

Hitchin and Harpenden MP Peter Lilley’s office confirmed that neither he nor any of his staff were in parliament today, ‘thankfully’.

Alistair Burt, MP for North East Beds, tweeted: “Police and security staff have ensured many of us are safe in difft places round parliamentary estate. Huge thanks. Awaiting further news.”

South Cambs MP Heidi Allen tweeted: “I’m fine as are colleagues but it seems one of our policemen has been stabbed and the assailant shot by police. We are all locked in.”

Reports indicate that a car ploughed into pedestrians while driving across Westminster Bridge before smashing into the perimeter wall outside parliament, with a group of people then rushing the gates in a bid to get away from the attack.