Boris Johnson has been urged to abandon half-measures and restore the “entire police team” following his pledge to beef up rank-and-file with 20,000 new officers.

Austerity measures have put paid to the jobs of 42,500 officers, police staff and PCSOs since the Coalition government came to power in 2010.

The Prime Minister’s promise to start recruitment “within weeks” will only work if the three-year plan also bolsters police staff and community support officer numbers by an estimated 22,000.

Without an extra 14,500 police staff and more than 7,000 PCSOs, the ambitious officer additions will not fix the “deep seated problems that nearly 10 years of police cuts have caused”, Humberside Unison branch secretary Tony Green believes.

It’s down to simple arithmetic – four police staff are needed to put six officers on the streets.

And Mr Green argued: “Police officers are just one part of the whole team.

“That is why Unison is calling on the Government, the National Police Chiefs’ Council and the Association of Police and Crime Commissioners to rebuild the entire police workforce, not just part of it.”

Mr Green added: “In the same way that recruiting 20,000 new hospital doctors will not cure more patients if they are not supported by more nurses, porters, radiographers, so 20,000 new police officers will not be able to patrol the beat and tackle more crime – without corresponding investment in the police staff and PCSOs to work alongside them.”

Police staff, including PCSOs, make up 40 per cent of the police workforce. "In simple terms it takes four police staff to put six officers on the beat,” he added.

“Not enough police staff means less time for officers on the street, as they are tied up with paperwork back in the station.”

Translating that in numbers, he explained: “To be effective in cutting crime, the restoration of 20,000 police officers will require the recruitment of an additional 14,538 new police staff and 7,371 new PCSOs to replace those cut since 2010.

"This is a total of 22,000 new employees.

"Unison calls on the Home Office and the police service to rise to the challenge of restoring the entire police workforce to its 2010 level, not just part of it.

“We need to rebuild the whole police team."

On the recruitment, the NPCC says substantial growth in officer numbers is a generational opportunity and will ease the pressure on people while helping reduce crime and improve outcomes for victims.

A spokesman added: “It is also an incredible opportunity to accelerate our plans to increase diversity in policing. 

“We will work closely with the College of Policing and the Government on the detail and practical implications of such a significant recruitment drive.”