Officers from every police force in the country have gathered in London today for the funeral of hero PC Keith Palmer who was killed in the Westminster terror attack.(Photos/VCG)

Thousands of police officers across Britain marked a two-minute silence on Monday to coincide with the funeral of Constable Keith Palmer who was killed in last month's attack outside parliament in London.

Palmer was fatally stabbed by Khalid Masood who had ploughed a rented car into pedestrians, killing five in total before he was shot dead.

Hundreds of uniformed officers lined the cortege route from a chapel at the parliament building where Palmer's body had lain overnight to Southwark Cathedral beside the River Thames.

A floral tribute on the hearse to the 48-year-old who was married with a daughter simply read: "No. 1 Daddy."

Among mourners at the cathedral was new London police chief Cressida Dick, on her first day in the role.

Sara Thornton, head of the National Police Chiefs' Council, told the BBC: "I don't think we will have ever seen a police funeral of this size..."

Palmer had not hesitated to act when confronted by a terrorist, she said.

"His bravery and his courage are something that all officers are very proud of," she added, "but also there is a tremendous sense of sadness and of loss."

Palmer's name was also added to the National Police Memorial, which records the names of those killed in the line of duty, during a ceremony in London.