The “barrage” of betting advertisements around Boxing Day sporting fixtures will exacerbate Britain’s growing gambling problem, NHS bosses are warning.

Promotional techniques by unscrupulous betting firms, including free Christmas bets, will increase gambling-related harm by encouraging punters to wager sums they cannot afford, they say.

Gambling addiction is causing so much damage that the NHS in England has almost doubled from eight to 15 in the last year the number of specialist clinics it runs to help addicts, it said.

The health service is facing “an uphill battle” to provide enough care to the increasing number of people whom GPs are referring to its network of clinics with gambling-related health problems.

Dr Matt Gaskell, the head of the NHS Northern Gambling Service, urged people who come into money as a Christmas gift or bonus not to risk losing it by using it to place wagers.

“People may receive extra money as gifts or bonuses during the holiday period, or find that money is short, and could be tempted to place a bet and end up betting more than they intended.

“With the barrage of adverts promoting festive fixtures, races and offers, such as free Christmas bets, it can make it look enticing, but these tend to encourage people to bet at high frequency,” said Gaskell.

“I have seen at first hand at my clinic how the festive period can lead to additional gambling harms.”

NHS England’s clinics offer mainly psychological help to people suffering from gambling-related problems such as mental ill-health, risk of suicide and relationship breakdown. They stretch from Newcastle and Preston in the north to Southampton and Thurrock in the south.

The number of referrals the clinics accepted has risen almost threefold from 775 in 2020/21 to 2,284 in 2023/24 as the number of openings has expanded to meet growing demand.

They expect to treat at least 3,000 people this year, now that 15 clinics are open. A record 1,914 problem gamblers were referred during April to September in 2024, more than double the 836 referrals received in the same period in 2023.

“The 24/7 gambling industry is causing ever-increasing harms with addictive products and an inescapable barrage of advertising – particularly through mainstream sporting events, with gambling firm logos on football shirts and eye-catching ads during the breaks of televised matches – which drive growing numbers to gamble beyond their means and control,” said Claire Murdoch, NHS England’s national director for mental health.

“The NHS is tackling an uphill battle to provide care to more and more people affected by this modern scourge and the predatory tactics used by shameless gambling firms to bolster profits.

“Addiction is a cruel disease that can take over and ruin lives. The NHS cannot be left alone to pick up the ills caused by firms engaging in activities that fuel addiction.”

Anyone struggling with a gambling problem, or who is close to someone who is, should ask the NHS for help, Murdoch added. She urged firms to be more responsible and “think hard about the potential harms to people behind their profits”.

Ministers recently unveiled plans to impose a new statutory levy on gambling industry profits, which is intended to raise £100m a year. Proceeds will be spent on research into problem gambling and how to prevent and treat it.

GambleAware, a harm reduction charity funded by the industry, endorsed the NHS’s concern that Christmas gambling adverts posed particular challenges for people who bet regularly.

“Gambling harms can affect anyone and Christmas can be a particularly difficult time of year for many.

“Having so many sporting fixtures during the Christmas holiday, with lots of gambling advertising around them, can make it hard for people”, said Zoë Osmond, GambleAware’s chief executive.

“This is why we have been calling for a ban on gambling advertising in sports to prevent gambling being normalised, particularly for children and young people who will be watching.”

The National Gambling Support Network, which helps problem gamblers across the UK, has treated almost 11,000 people this year – 12% more than last year. And calls to the National Gambling Helpline have reached 55,000 a year.

In October, the Lancet medical journal’s commission on gambling warned that betting posed a worldwide threat to public health. It is also associated with domestic violence, other crime and people losing their jobs, its panel of experts said.

Globally, about 80 million adults suffer from gambling disorder or problematic gambling, with adolescents, children and poorer people the worst affected, it found.