The combination of new-style casinos and extended drinking hours will create a "lethal cocktail" of super bars in town centres catering for thousands of drinkers at a time, the Conservatives said last night.
An investigation by the party claims that moves by the Government to set up a series of "smaller" casinos around the country could "threaten public welfare".
Already, up to eight "super" casinos may be built following the introduction of the Gambling Act 2005.
But the Conservatives' report focuses on the proposed breed of what they describe as "large" and "small" casinos which, it claimed, could hold as many as 3,000 customers.
New rules under the act would force these casinos to set aside space for non-gambling purposes, resulting in storey upon storey of bars, open until 6am.
Theresa May, the Tory spokesman on culture, media and sport, said: "Even so-called smaller casinos will dwarf anything seen before in Britain.
"I fear the new casinos will combine with super-bars; behind the superficial glamour of poker or black-jack, the real money will be made from slot machines and plying alcohol into the early hours.
"The combination of weaker gambling and licensing laws threatens a lethal cocktail that will threaten public welfare."
Mrs May also warned that a plethora of jackpot-style machines would encourage drinkers to gamble more.
She said: "Casinos will also operate as super betting offices. Apart from the slot machines and gaming tales, the will be able to offer an unlimited number of smaller prize slot machines."
A spokesman for the Department of Culture, Media and Sport, said: "British casinos will be the most tightly regulated in the world. Binge drinking will not be tolerated.
"The Gambling Commission will have the power to revoke licences and there will be heavy fines imposed on casinos acting irresponsibly."