Burnham urged by 50 police leaders to prevent early release of PC Harper’s killers

Letter signed by every chief constable in England and Wales warns freeing pair could weaken trust in justice system

Andy Burnham is facing an unprecedented mass call from police chiefs to block the early release of PC Andrew Harper's killers, as unions warned his emergency plan to create more space in jails risked causing confusion or leading to prisoners being freed by mistake.

A letter signed by 50 police leaders across the UK, including every chief constable in England and Wales, called on the prime minister to do everything in his power to stop the killers benefiting from a programme designed to free up prison space, saying there was a profound strength of feeling across policing" that this should not happen.