Casinos and bookmakers in Great Britain will be forced to pay a £100m-a-year levy to fund research, education and treatment of gambling harms, under government plans to be announced as soon as this week.

Labour is understood to be poised to rubber-stamp the previous government’s proposal to do away with a voluntary system that allows industry operators to choose how much to donate to tackle damage caused by gambling and which organisations should receive the money.

The levy, which multiple sources said could be announced by gambling minister Baroness Twycross as soon as Wednesday, is expected to take effect from next April, the Guardian understands.

Under the terms of the “statutory levy”, gambling firms will be told that they must pay 1% of their gross gambling yield – what they win from British gamblers – to support research, education and treatment causes.

Based on figures from the Gambling Commission, which showed that the industry won £10.9bn from gamblers in Great Britain in the last 12 months, this would raise £109m.

However, a consultation on the proposal, published last year, envisaged a lower rate of 0.4% for land-based operators that have higher costs, such as high street bookmakers and casinos. The consultation also said firms with gambling revenues of less than £500,000 would be excluded.

Iain Duncan Smith, who chairs an all-party parliamentary group (APPG) of MPs examining gambling harms, said: “I am delighted that the statutory levy, which the APPG first proposed five years ago, is finally being introduced.

“For the first time the gambling industry will be mandated to pay for the harm they cause. Whilst there is much more to do but this is a seismic moment and a huge step forward and I welcome it unreservedly.”

Recipients of the money raised are expected to include a fleet of new NHS specialist addiction clinics, as well as a range of small charities providing services such as education in schools and counselling for people affected by gambling-related suicide.

One bone of contention could be how much, if any, of the funds for prevention of gambling-related harm are diverted to the UK’s leading gambling charity, GambleAware. Under the current voluntary system, the charity is the largest on a list of approved recipients for industry money, receiving nearly £50m in donations and pledges between 1 April 2023 and 31 March 2024.

Sources familiar with the plans said the Office for Health Improvement and Disparities (OHID) was vying with GambleAware to be the government’s preferred destination for funds collected under a statutory levy.

The gambling minister, Baroness Twycross, is scheduled to speak at GambleAware’s annual conference in December, an engagement that could prove tense if the government excludes the charity from official funding channels.

The industry lobby, the Betting & Gaming Council, said that it would support a statutory levy, when the policy was listed among proposals in a white paper published by the Conservative government in April 2023.

The lobby group appears to have changed its mind as political support for the measure gathered pace. The former chair of the BGC, Brigid Simmonds, wrote in 2022 that imposing a levy on the industry would be a “backward step” that would have no impact on gambling-related harm.

On Monday, a spokesperson for the Betting and Gaming Council, said: “The BGC previously proposed a mandatory levy and we welcomed the government’s announcement for a new system of payments with continued independence of funding allocation.

“The BGC remains concerned that there should be a sliding scale for land-based businesses that have much higher fixed costs, such as staff and premises, and that funding for longstanding, expert providers of research, prevention and treatment services in the third sector is protected.”

The Department for Culture, Media and Sport declined to comment.