More gambling addicts will die as a result of a year-long delay to reforms, the government has been warned, as experts called proposals published on Thursday a “missed opportunity”.

The Department for Culture, Media and Sport (DCMS) published a 268-page white paper laying out a shake-up of existing regulations, which date from before smartphones put access to 24-hour casino games and sports betting in every pocket.

The content of the proposals, which have already been delayed on at least four occasions, met with broad support from MPs and campaigners but drew criticism for shying away from curbs on advertising.

The proposed reforms include:

• A mandatory levy on industry revenues.

• Tougher affordability checks to prevent huge losses.

• Online slot machine stakes capped at between £2 and £15.

• Curbing “free spin” and “bonus” offers.

• Measures to slow down online casino games.

• More resources for the Gambling Commission.

• Plans for a gambling ombudsman.

Some of the measures, such as affordability checks and online slot limits, will be tighter for people aged between 18 and 24, who are at greater risk of addiction.

The culture secretary, Lucy Frazer, told the House of Commons that the white paper would improve controls on an industry that could, at its worst, “wreck lives”.

She said ministers were “bringing pre-smartphone regulations into the present day with a gambling white paper for the digital age”.

Nearly all of the measures will go out for further consultation by the Gambling Commission and the DCMS, which will have a year to finalise the finer details in time for planned implementation in summer 2024.

Experts, campaigners and MPs expressed concerns about further delay to a process that began in late 2020, when the government launched a review as promised in Boris Johnson’s 2019 election manifesto.

Dr Matt Gaskell, a consultant psychologist who runs the NHS Northern Gambling Service, said the consultation meant that “the industry will carry on making huge profits while people are suffering and dying”.

Labour’s Carolyn Harris, who co-chairs a cross-party group of MPs examining gambling harms, hailed a “momentous day” but said it was time for “swift and immediate action” rather than fresh delays.

The white paper contained no significant measures to crack down on gambling advertising. Prof Henrietta Bowden-Jones, a leading addiction expert speaking on behalf of the Royal College of Psychiatrists said she was “disappointed” at the lack of measures to curb gambling ads and sponsorship.

“Like alcohol and tobacco, there is a very strong case for prohibiting or severely limiting gambling advertising and sponsorship on public health grounds,” she said.”

The Money and Mental Health Policy Institute, set up by personal finance guru Martin Lewis, echoed calls for curbs on advertising and said it was “frustrating” that so many measures are going out for consultation.

The shadow culture minister, Lucy Powell, accused the government of dragging its feet, saying: “There’s no reason we can’t get all this done by the Summer recess.”

The campaign group Gambling With Lives, co-founded by parents Charles and Liz Ritchie after their son, Jack, took his own life, said it would keep pushing for a total ban on all gambling advertising.

Ministers are thought to have been reluctant to curb advertising because they were unconvinced that it has a significant impact on gambling behaviour. Earlier this year, Premier League football clubs voted to forego gambling sponsorship on players’ shirts from 2026 but elected to keep pitchside displays, the most visible form of gambling advertising.

While the government expects its proposals to reduce gambling industry income by as much as £800m, shares in the largest gambling companies actually made gains, signalling investors’ relief that the plans, many of which had been leaked in advance, were not harsher.

The white paper will update the 2005 Gambling Act passed by a Labour government under Tony Blair that liberalised laws governing the sector in an attempt to foster a world-leading industry.

It will loosen regulation of land-based casinos, which will be allowed to install more gaming machines, offer sports betting and offer credit lines to high-rollers from overseas.

Instead, it will crack down on online gambling, which now accounts for the majority of the £10bn that the sector generates from British punters every year, excluding the national lottery.

Frazer said the rapid growth of internet gambling meant the industry was “unrecognisable” compared with the pre-smartphone age and that addicts were suffering extreme harm.

She said: “When gambling becomes addiction, it can wreck lives. Shattered families. Lost jobs. Foreclosed homes. Jail time. Suicide.

“These are all the most extreme scenarios, but it is important we acknowledge that for some families those worst fears for their loved ones have materialised.”

A string of high-profile tragedies and broader concerns about addicts, vulnerable people and children have triggered growing calls for ministers to act. Despite the increased spotlight on the industry, high street bookmaker William Hill was fined a record £19.2m last month after allowing multiple customers to lose tens of thousands of pounds within minutes of opening an account.

According to a government impact assessment, the measures could reduce industry revenues by 8%, equivalent to £800m. The white paper said that “much of this will be foregone revenue from customers who were being harmed by their gambling”.

Paddy Power owner Flutter told the stock market that the changes could cost it between £50m and £100m a year.

Yet shares in London-listed gambling companies, such as 888, Paddy Power owner Flutter and Ladbrokes owner Entain, rose on Thursday.

This article was amended on 27 April 2023. The DCMS is now the Department for Culture, Media and Sport. It no longer has responsibility for Digital, as an earlier version said.