Labour is expected to confirm new affordability assessments for online gamblers who incur heavy losses, despite opposition from the betting industry.
Under the proposals, gamblers losing more than £125 in 30 days or £500 in a year would face basic checks using public records.
Those losing more than £1,000 in 24 hours or £2,000 over 90 days would trigger enhanced checks using credit-reference data.
Ministers insist the measures are not affordability checks and will not cap spending, but are intended to identify customers in serious financial difficulty.
An industry source said: "The Gambling Commission is rushing into the biggest policy change this industry has ever seen, at the same time it’s struggling to recruit a new chairman, a new chief executive, and most of its officials seem to be leaving to advise the private sector."
The source added: "It’s a farce, and the whole thing risks yet another windfall for illegal gambling operators."