Home Secretary Theresa May has joined hundreds of police to remember officers who have died on duty, including the two Pcs killed two weeks ago in Manchester.
Dozens of chief constables packed into York Minster, together with colleagues of all ranks and the families of officers who have died, for a service to mark National Police Memorial Day.
Meanwhile, Labour opened its annual conference in Manchester with a tribute to the police and a minute's silence in memory of two officers who died in a gun and grenade attack.
MP Jonathan Reynolds reflected on events earlier this month in his Stalybridge and Hyde constituency when Greater Manchester Police officers Fiona Bone and Nicola Hughes were shot and killed.
Delegates at the Manchester Central conference venue stood in silence following Mr Reynolds' tributes, the Press Association reported.
Speaking as he arrived outside York Minster, the chief constable of Greater Manchester, Sir Peter Fahy, said the recent deaths of Pcs Bone and Hughes in the Mottram area of his force made the day even more poignant.
He said: "It does give it a special poignancy because it's close after the deaths of Fiona and Nicola but the important thing today really is remembering all the officers who have given their lives during the year.
"I cannot tell you how much we have been uplifted by the public response, it has been quite extraordinary. It really does show the level of support for ordinary officers going about their day to day business.
Sir Peter said: "We try to remember all of those officers and also tell their families that the sacrifice of a loved one is not forgotten and that is a really important part of the service today."
Among the other officers remembered by the 2,000 people inside The Minster was Pc Ian Dibell, who was killed near his home in Clacton, Essex, while intervening in a row in July. He was not on duty at the time.
Flowers laid in tribute to fallen officers Fiona Bone and Nicola Hughes, who were killed on duty in Hattersley
Association of Chief Police Officer President Sir Hugh Orde said: "The National Police Memorial Day provides an opportunity for the whole police family to come together and remember police officers who have died protecting the communities they served.
"Today is particularly poignant as the losses of Pcs Fiona Bone and Nicola Hughes in Greater Manchester and Pc Ian Dibell in Essex are still so raw.
"The tributes to these officers have shown policing was a true vocation for them.
"We have heard that it was a job Fiona and Nicola loved, and Ian showed his commitment to protecting others even when off-duty, as so many police officers routinely do.
"We commemorate them and their contribution to policing, along with those that the police family has lost in the past.
Our thoughts are with their families, friends and colleagues."