Nottinghamshire police are "over-stepping the mark" in threatening to force pubs in Retford and Worksop to serve drinks in polycarbonate glasses on the busiest nights, according to legal expert Peter Coulson.
Two weeks ago, a 32-year-old man was sentenced to 15 months in prison after admitting glassing another man in the Litten Tree in Retford. The pub now uses polycarbonates on a Friday and Saturday.
But police have said they will deal "robustly" with people who carry out glassings and licensees who refuse to use polycarbonates.
"Glassing incidents are very, very rare, but each one has the potential to cause serious or even potentially life-altering injuries to the victims," said Sergeant Andy Wilson.
"When they do occur we will ensure that the offenders will be brought before the courts, and we will urge the courts to hand down custodial sentences.
"However, we also need the co-operation of the licensing trade. We are asking for all pubs in Worksop and Retford town centres to serve drinks in polycarbonate glasses on high days and holidays.
"If they don't comply we have the power to call an expedited review of the licensing conditions. That review could result in the licensee being required to serve drinks in polycarbonate glassware at all times."
Police are continuing conversations with Pubwatch over implementing a voluntary scheme.
However, Coulson said police were over-stating their powers as an expedited review can only happen when there was actual or an imminent risk of serious crime and disorder.
He also stressed that police could not impose blanket conditions without specific evidence of glass-related incidences at a particular venue.
"They can't make a global demand — they are not entitled to do that. They would have to tie specific incidents to specific pubs. The police are mis-stating the law."