Police officers about to retire could be offered pension incentives to retain them and help hit Boris Johnson’s target of 20,000 extra police in three years.

A working group of senior police chiefs will consider expanding a scheme pioneered by Scotland Yard to combat a shortfall of experienced officers taking on cases including murder, rape and other serious crime.

Rather than taking permanent retirement, officers are offered the chance to return to their post at the same rank and salary with the added bonus of first being able to draw a six-figure lump sum from their pension.

If they had stayed beyond the standard 30 years, they would have been penalised with no extra benefit to their pension. This alternative allows them to return and either to take the pension contributions as extra pay, or open an additional personal pension.

The move would aim to retain a portion of the 6,000 police officers who quit or retire every year, to help meet what the Prime Minister has promised will be a net gain of 20,000 officers.

It is understood about £500 million has been set aside to start recruiting the first 6,000 officers from September. It will include national and local campaigns to promote police as a career.