THOUSANDS of police officers, including those from Wiltshire, have gathered to remember PC Keith Palmer, who was murdered in the Westminster terror attack.

PC Palmer, 48, was stabbed to death by Khalid Masood as he carried out his duties on the cobbled forecourt of the Palace of Westminster.

Officers from forces all over the UK lined the route his funeral cortege took from the Palace of Westminster, where it laid in rest overnight, to Southwark Cathedral.

His coffin travelled along 2.6 miles of the capital's usually bustling streets, avoiding the scene of last month's atrocity on Westminster Bridge.

Hundreds of officers arrived in Southwark, hours before the funeral, while members of the public began to line the barriers along the cortege route.

Columns of uniformed officers, many with service medals pinned to their jackets and wearing white gloves, marched towards the cathedral as on-duty colleagues involved in the large security operation stood guard.

Wiltshire chair of the Police Federation Inspector David Ibbott, who attended the funeral, paid tribute to the selfless actions of PC Palmer.

He said: “The force has undoubtedly lost one of its finest officers.

“It was a very emotional and moving experience. I think every police officer from across the country was represented.

“It was clear that PC Palmer was a very much respected officer.

“He stepped in front of danger to stop that man going any further. He sacrificed himself and stopped that man killing more people."

Inspector Ibbott said the show of support from thousands of police officers sent a clear message to terrorists.

He said: “It doesn’t matter where you are from, we are all one big family at the police and it is important to show our respect to PC Palmer and his sacrifice

“It is also an act of defiance, to say that these people cannot win and we will stand strong together as one unit and as a country. We are not afraid and we are united.

“They mustn’t win.”

Assistant Chief Constable Kier Pritchard, the chief officer representing Wiltshire Police, said: “PC Keith Palmer tragically died whilst serving to protect the public as a highly respected member of the Metropolitan Police Service.

"Although today is an opportunity for his family and friends to celebrate his life, it is also a day for his colleagues, across the wider police family, to show respect and gratitude for his service.

"Today, alongside a number of uniformed colleagues from Wiltshire Police, I will be attending the funeral service in Southwark Cathedral to pay our respects to Keith.

"It is vital that police colleagues are able to come together to show strength and solidarity in honour of Keith and every officer who dedicates their lives to protecting the public."

Chief Constable Sara Thornton, head of the National Police Chiefs' Council, said the scale of the funeral will be unprecedented as officers hold a two-minutes' silence at 2pm.

She told the BBC's Victoria Derbyshire Show: "I don't think we will have ever seen a police funeral of this size.

"Officers from all over the country are coming to London to join their Metropolitan Police colleagues to line the route.

"But at 2pm outside police stations across the country, officers and staff will be observing a two-minutes' silence.

"We all want to pay honour to the ultimate sacrifice that Keith made."

The Queen gave permission for PC Palmer's body to rest in Westminster's Chapel of St Mary Undercroft, an honour normally reserved for senior figures.

Ms Thornton said the gesture had had a "tremendous impact" on police as they go about their duty.

She said: "The fact Keith has laid in rest in the Palace of Westminster is a sort of acknowledgement on behalf of the whole country of the sacrifice that he made but also the job that officers do day in, day out."

Full service funerals are normally only held when a police officer or member of staff dies while they are carrying out their duty, Scotland Yard said.

The last full police funeral for a Met officer killed in the line of duty was in October 2013 for PC Andrew Duncan, who was killed the month before after being hit by a car while checking vehicle speeds in Sutton, south London.

PC Palmer's name has been added to the roll of honour and remembrance at a ceremony at the National Police Memorial on The Mall, in central London, complete with a guard of honour.

Steve Lloyd, of the Police Roll of Honour Trust, said: "It is right that the men and women of the British police service who have paid the ultimate price in the service of this county be remembered here at the national memorial on this record of historical importance.

"We hope that knowing their loved one's name are to be forever remembered will bring some small comfort to the families of the fallen officers."

The name of former PC Gareth Browning was also added after he died aged 36 more than three years since being seriously injured when he was hit at high speed by a stolen car while on duty.

Four other innocent people were killed and dozens of others injured in the 82-second atrocity on Wednesday March 22, which ended with Masood, 52, being shot dead.

Andreea Cristea, 31, Leslie Rhodes, 75, Kurt Cochran, 54, and Aysha Frade, 44, died after he ploughed into pedestrians on Westminster Bridge.