PRESS ASSOCIATION --- Thousands of police officers are to call on the Government to come to the negotiating table as they join a day of action against cuts to the service.
More than 2,000 off duty rank and file officers are due to attend an open meeting to warn that the spending squeeze could fuel crime.
Shadow home secretary Yvette Cooper, Keith Vaz MP, Sir Hugh Orde, president of the Association of Chief Police Officers, and Brendan Barber, general secretary of the TUC, have been invited to speak.
Paul McKeever, chairman of the Police Federation of England and Wales, will say he has "no doubt that a 20% cut to overall police budgets will lead to more crime".
"It simply won't be possible to provide the same level of service to the public that we do now if we are losing officers, support staff, vehicles and stations," he will say.
"We accept that cuts have to be made but we ask that the Government acknowledges our unique status; police officers do not have industrial rights, so it is vital that the Home Secretary honours the police pay negotiation process."
The federation is calling for a "fair negotiation process and honesty about the implications of cuts to policing", he said.
"The public has a right to know what the likely impact will be if 20% cuts are imposed," Mr McKeever added.
The day of action at Central Methodist Hall, Westminster, comes after Theresa May refused to relent on her police cuts during her annual keynote speech to police leaders.
Anger has been building in frontline policing since former rail regulator Tom Winsor said the most wide-ranging analysis of forces pay in 30 years showed more than £1 billion of savings should be made.