The Gambling Commission revealed almost £4.7bn was bet online in 2016-17, a rise of 10% and more than was spent on the National Lottery.

The watchdog warned operators that with “such growth comes a responsibility” to prevent gambling-related harm.

It predicts more than half of all gambling will be done online “in the near future”.

Spending online increased by more than £428m in 2016-17 compared with the year before, while spending on the National Lottery fell £438m. Total spending on gambling increased £249m.

The figures come as the regulator has said it will be more “interventionist” and will require operators to do more to tackle addiction to online gambling.

A third of the £13.7bn spent on gambling in Great Britain now goes online and the Gambling Commission says the technology is “too often weighted in favour of the gambling operator” rather than the gambler.

The total online spend accounts for more than either the National Lottery or betting shops.

Commission executive director Tim Miller said: “These latest figures show that the gambling market is continuing to grow, particularly in the online sector.

“However, with such growth comes a great responsibility for operators to prevent gambling-related harm to all consumers and the public. We would urge all gambling businesses to be acutely aware that as their market grows so too will our focus on ensuring that consumers are protected.”

From spring 2018, online gamblers who want to stop will be able to “self-exclude” from a single site. The move is intended to help people who may have already opted out of gambling with one operator also stop gambling with others.