A senior Nottingham policeman has vowed to continue trying to close pubs that serve under-18s after 12 pubs and bars failed the latest test purchase operation.
Despite the fact that all 16 venues that failed a previous sting passed the latest one on 9 September, Inspector Paul Winter said operations would be stepped up after the recent failures.
The famous Ye Olde Trip to Jerusalem was among the outlets that failed - and the pub's manager hit out at the "unfair" tactics of police.
Winter said that of 42 pubs and bars targeted in the latest sting, 12 served youngsters under 18. Most of those failing the test came from outside the city centre. Bar staff who served the children were slapped with an £80 fine.
Nottingham Police usually asks the council to review a venue's licence if it fails three stings.
"Licensees need to expect that we could inspect them any day, at any time," said Winter. "If we tested a venue this month and they failed, we would test them again."
Nottingham has a reputation for carrying out rigorous sting operations and taking action against venues that are caught serving under-18s.
The Bunkers Hill pub was ordered not to serve alcohol for two weeks after police asked for a three-month alcohol ban.
The Broadway Café Bar, a real ale pub in an art house cinema, had its licence suspended for six weeks.