The Gambling Bill has been approved by the House of Lords after the government scaled down plans for eight regional "super-casinos" to just one.
The bill looks set to become law before Parliament is dissolved
It completed all its Lords stages on Wednesday and is set to become law when it returns to the Commons later.
The bill appeared doomed until Culture Secretary Tessa Jowell struck a deal with Tories to create just one casino.
The bill now looks likely to be approved before Parliament is dissolved on Monday for the general election.
Liberal Democrat Lord Greaves said if the single "super-casino" was going to be created in Blackpool, as reports have suggested, he did not believe there would be "dancing in the streets".
He said if the Lancashire seaside town was selected, the local council should first hold a referendum to gauge the public's views.
The bill - which was given a third reading without a vote - will allow casinos to open 24-hours-a-day with unlimited jackpots.
It will also introduce compulsory age checks on gambling websites, set up a new Gambling Commission to police the industry and create a new offence of permitting a child to gamble.
The location of the new "super casino" will be decided by an independent panel.
The Gambling Bill originally included plans to allow an unlimited number of such casinos, with up to 1,250 slot machines.
But the plans were reduced to eight following pressure from Labour backbenchers and charities.