An MP who fought to save the life of a police officer during last year's Westminster terror attack has told how he closed his eyes and apologised in the moments after his death.

Tobias Ellwood rushed to help PC Keith Palmer after he was stabbed by Khalid Masood on March 22.

Holding back tears as he spoke at an inquest into the victims' death, the MP said: "[We] closed the eyes and then I said 'I'm sorry'."

Four others died after Masood drove into them on Westminster Bridge.

The inquest into the deaths of PC Palmer, 48, Kurt Cochran, 54, Leslie Rhodes, 75, Aysha Frade, 44, and Andreea Cristea, 31, is taking place at the Old Bailey in London.

An inquest into the death of Masood - who was shot dead by armed police during the attack - will take place afterwards.

Mr Elwood, who was at a meeting nearby when the attack took place, told how he ran through the crowd and saw PC Palmer lying on the ground.

The former soldier told the inquest that, despite the risk attacker Khalid Masood may have had a bomb in his abandoned car, his main concern was giving help to the stricken officer. 

The MP, whose brother died in Bali in 2002, said: "My brother was killed in a secondary attack ... so I was very aware of that.

"I was concerned about what would happen if things were to ratchet up, but my immediate concern was that we had somebody who was clearly badly bleeding and needed assistance."

Mr Ellwood said PC Palmer was unconscious when he approached, but that he still had a pulse, telling the court: "I was encouraged that we'd arrived on the scene early enough to do something."

The MP commenced CPR, which he continued after paramedics and doctors from the helicopter ambulance team arrived.

When it became clear PC Palmer would not survive, Mr Ellwood told a doctor present: "You’re going to have to order me to stop".

The medic said: "Sir, you’ve done your best but you do need to stop."

Another member of the public who helped PC Palmer, Anthony Davis, told the inquest that he said "come on son, stay with us" to the stricken officer.

Mr Davis described seeing "blood pooling in between the cobbles" as the extent of PC Palmer's injuries became clear.

Both he and Mr Elwood were left with the officer’s body.

The MP said: "We both covered the body as best we could, closed the eyes and I said: 'I’m sorry.'

"It was very, very silent, it was a very strange end to a very traumatic four or five minutes, to suddenly be left completely alone with just one other person."