Witness fleeing attack takes shelter in Yorkshire MP's office

The American student was among a group of visitors fleeing the scene of the attack when they met Mr Percy near the Commons chamber.

He said the man described how he had witnessed the attacker stab the police officer in the courtyard outside Parliament.

Mr Percy told The Yorkshire Post: “This group of people came running up the stairs and I told them they couldn’t go in because there was a vote happening.

“They said there had been an incident, shots had been fired and there was a man with a knife.

“By this time they had barricaded the chamber off. I had to make a judgement call so I decided to take them into my office.

“They were pretty shaken and my thought was that we have got to get people hidden away.

“As I got to the office my staff were starting to leave and I ordered them back in, we locked the doors, closed the curtains and put our phones on silent.”

Mr Percy said the group had been “50 to 100 feet away” from the attack when it happened.

“One of them saw the attacker, he saw him stabbing the police officer repeatedly.

“He had thought he heard cheering but in fact it was screaming,

“They heard gunshots, they started running and that’s when they ran into me.

“They are very very frightened.”

Mr Percy said the American visitor who saw the attack had also been at the scene of the Boston bombing in 2013.

Halifax MP Holly Lynch was returning to a meeting in the Shadow Cabinet room following a Commons vote when news of the incident began to filter through.

The group in the meeting barricaded themselves in the room as they heard reports there could be an attacker at large on the Parliamentary estate.

She said: “At one point there was a lot of shouting outside the room which was pretty distressing but I think it was just the police trying to clear the area.”

Ms Lynch is the daughter of a retired police officer and has campaigned strongly over the safety of police and the sentences handed to those who attack officers.

She said: “Having been out with the police in my constituency I am well aware of how hard they work and the risks they face every day.

“I didn’t imagine an officer would have to make the ultimate sacrifice protecting MPs and those who work in Parliament.

“He has the gratitude and respect of all of us here and our thoughts are obviously with his family.

“We are all going to have to reflect on the safety of the police and the issues this raises more broadly.”

Wakefield MP Mary Creagh took the exit from Parliament to Westminster station where she urged underground staff to take action.

She said: “The one thing we don’t want is a whole load of tourists walking up and wandering in with their children into this situation.

“I went to the control room, I told the controller there had been what we thought was at terror attack on the Palace of Westminster and I said ‘you’ve got to shut this station now’.”

Ms Creagh said she spoke with “the authority that sheer panic gives you”.