Lincoln police are accused of overstepping the mark by forcing pubs to close temporarily for "petty" reasons.
Essence, in Lincoln, shut after failing to display a sign reminding customers to leave quietly and not logging full badge numbers of doorstaff.
The nearby Quayside, which failed to produce up-to-date toilet check records and detail full contact details of all door supervisors, also closed temporarily.
Both bars breached licence conditions and were temporarily closed after being issued with Section 19 Closure Notices. A dispute has emerged over whether the powers can be used this way.
MA legal editor Peter Coulson highlighted Home Office guidance that says police can seek a closure order, via magistrates, if the closure notice isn't adhered to within seven days.
"Nowhere does the new guidance advocate instant closure," Coulson stressed.
The guidance says the notice doesn't give police powers to clear premises of customers.
A police spokeswoman said the notice did not actually shut the venues — it only stopped them conducting licensable activities such as selling alcohol.
"When we issue a closure notice it is always emphasised that licensable activities must cease. As long as they do not conduct licensable activities while in breach, they can remain open."
However, Coulson said: "I disagree. Just because they are breaching a minor condition, doesn't require them to cease licensable activities."
Essence manager Mark Welford said the closure for "petty things" was "absolutely ridiculous". Although the Scottish & Newcastle Pub Company venue reopened the next day, Welford said people have stayed away. "We are probably down by a couple of thousand pounds a week," he said.
Michael Kheng, boss of Kurnia Group and chairman of Lincoln Uphill Pubwatch, said he was "disappointed" by the police's apparent "heavy handed" approach.