A loophole that allows gambling websites to offer cut-price bets on the EuroMillions draw, taking money away from good causes, will be closed by the government.

People can bet on the outcome of the EuroMillions draw with a £2 stake on websites such as Lottoland, which is fronted by Chris Tarrant, even though the Gambling Act prohibits betting on National Lottery games.

Websites get round the law by offering Britons bets on EuroMillions in other countries, such as Spain. But the EuroMillions draw is the same in every participating country and takes place every week in Paris. The government intends to change licence regulations to stop the practice.

Tickets in the genuine EuroMillions draw cost £2.50 each and a third of that goes to good causes. There are fears that if action is not taken then official ticket sales will continue to slide and draw money away from these beneficiaries.

The lottery raises cash for the arts, sport and heritage projects in the UK as well as supporting charities and volunteering.

Tracey Crouch, the lotteries minister, said: “We want to act to ensure that money going to good causes is protected and that there is no confusion around the EuroMillions draw, providing the same levels of clarity as there is with the National Lottery.”

Since the National Lottery was set up in 1994 more than 500,000 good causes have benefited from a total of £36 billion.