Since the start of the coronavirus outbreak, Lancashire Constabulary has spent an extra £795k on responding to the crisis with the figure set to break the £1m mark by June, according to Mr Grunshaw.
He said that this 'unprecedented pressure on the police' has come at a time when savings of over £86m have had to be made to accommodate savings targets from government.
Mr Grunshaw has written to the policing minister, Kit Malthouse, to seek clarity and certainty to police forces at this difficult time to make sure that they are not punished for managing the impact of coronavirus on communities.
Mr Grunshaw said, "In these unusual times we have seen the importance of the police and other frontline services in keeping Lancashire safe from harm.
"I have written to the police minister, Kit Malthouse, to make sure that Lancashire will not be any worse off in responding to the coronavirus pandemic and seeking clarity over the position that we find ourselves.
"Whilst the government has allowed Lancashire Constabulary flexibility in how it is able to spend the grant provided for an additional 153 officers, there needs to be certainty in how we recoup the costs related to responding to coronavirus.
"The cost of coronavirus since March has been £795k and this figure will keep rising as we meet the challenge of responding to the virus and managing public safety. The people of Lancashire will expect that their police service is not short-changed and that money spent responding to coronavirus is replaced in full by government. Lancashire Constabulary should not be penalised for protecting its officers and the public.
"If we are to replace some of the 750 officers lost in Lancashire since 2010 and meet the government's own recruitment targets then we need certainty over funding. The people of Lancashire consistently tell me that they want to see frontline policing protected and I hope that government is able to provide some reassurance".