The Wigan Casino night club (1973-1981) was central to the Northern Soul movement. Club goers were known to use amphetamines so they could dance and enjoy music until morning. In the documentary This England by Tony Palmer, a young man being interviewed claims that it was a loophole in a local bylaw that allowed the Wigan to host all nighters: https://youtu.be/MDTL57_lmgE?t=562 (his claim is at 9:22)
"I don't think the fact that it's Wigan is terribly important. It's just that it's an easy place to get to. And with a slip up in the local bylaws, the Casino can stay open all night from Saturday to Sunday, as long as it doesn't serve any alcohol."
The police were fully aware of amphetamine use at the Casino, shown in this news article (halfway down the page) which was posted on a Northern Soul fan forum. The relevant quote is:
A drug squad officer is sticking to his claim that 98 percent of youngsters at Wigan Casino’s “all-nighters” are on drugs. […] Casino owner Gerry Marshall yesterday condemned the officer’s statements as ‘utterly ridiculous.’ “There is no drugs problem at Wigan Casino. We have our own Casino drugs squad made up of our own people and they sort anything out. We have only thrown out half a dozen people whom we have suspected of taking drugs.” said Mr. Marshall. A police spokesman for West Yorkshire Police said D.c. Swallow was preparing a report for the Chief Constable following the Recorder’s comments. A Wigan Council spokesman said they had not received the letter from West Yorkshire police but added: 'We can only act if there has been a breach of the terms of the lease.'
Although the article mentions 'West Yorkshire' police, the Wigan seems to have been under the jurisdiction of Greater Manchester police in its later years. As pointed out by user Henry in the comments below,
Wigan would have been covered by the Lancashire Constabulary from 1969 to 1974 and Wigan Borough Police before 1969.
Given that the police had checkpoints in the area to search clubbers, nearby chemist shops were broken into, and drugs were increasingly criminalized, it’s hard to imagine how the venue survived merely because of a local loophole.
Which law would have allowed the Casino to continue hosting all-nighters, despite disgruntled local authorities?