Under the proposals – set out in a consultation document by the Department for Culture last year – the standard opening hours for all casinos will require them to close between 6am and noon each day.
At present, casinos have to close between 6am and 2pm six days a week and 4am and 2pm on Saturdays.
However, the rules go on to give casinos the power to apply to their local authority for permission to extend their opening hours up to 24 hours a day.
"All casinos will of course have the opportunity of asking for the default hours to be changed when they apply for licences," the document said.
Critics warned that this will be seized on by operators who will seek permission to open round-the-clock.
They said that the local authorities who grant licences will have lobbied hard to win the right to open a casino in their area and will therefore be more inclined to approve applications for longer hours.
They also voiced concern that casinos may also be able to secure licences to serve alcohol 24 hours a day.
The new rules are a key element of Labour's overhaul of the gambling industry, which will see the location of Britain's first "super-casino" – along with the sites of a further eight large and eight small casinos – being unveiled on January 30 by the Government's advisory panel.
Dr Emanuel Moran, an adviser on pathological gambling to the Royal College of Psychiatrists, warned that 24 hour opening would be disastrous.
He said casino opening hours should be enshrined in legislation, rather than left up to local authorities to decide."In the 1960s, prior to the Gaming Act, there was a gambling free-for-all which saw many casinos open 24 hours a day and it had dreadful consequences," said Dr Moran, who helped set up Gamblers' Anonymous four decades ago."I remember once being called by a woman whose husband had spent three days in a casino and she pleaded with me to go in there to get him out.
It's crucial that casinos have to close each day to ensure gamblers have to take a break.
Any move back towards 24 hour gambling would be a recipe for disaster."Mark Griffiths, the professor of gambling studies at Nottingham Trent University who has advised the Government on the issue, added: "The fear for some individuals is that the combination of gambling and drinking is a heady mix that will exacerbate problem gambling.