Steve Kent said some sections of the public are already acting as if there are no restrictions in place and that it has become “increasingly difficult” for officers.
He said: “Large members of the community are already edging towards acting in a way that is normal, which in itself causes problems because the idea that police officers can still police this with current regulations is incredibly difficult.
“We’re already seeing people just going about their daily lives as normal and you only have to go into the public to see how much the compliance of face masks is dropping.”
Mr Kent said police officers would be put in an “impossible situation” if there is any sort of extension to lockdown rules.
He said: “Public compliance and willingness to comply is going.
“We’ve been warning throughout the whole year that this three-month period around the restrictions easing is going to be extremely challenging and I think it’s going to be some of the busiest times in recent years in policing.
Mr Kent said police officers have gone over and above the call of duty during the Covid-19 pandemic, working all hours and carrying out voluntary roles on the side.
A recent survey revealed almost nine out of ten police officers have done additional voluntary work or fundraised during the pandemic on top of their duties.
Research carried out for Public Service Day by Boundless - a membership club for civil service and public sector workers- revealed 88 per cent either volunteered or raised money during the Covid crisis.
Mr Kent said: “You see the very best of our police officers when there are difficult times.”