Tory MPs have been writing “sponsored content” online for the Betting and Gaming Council, a lobbying group campaigning for the gambling industry.

They include Jack Brereton, MP for Stoke-on-Trent South and a government aide who wrote an article published on the ConservativeHome website on Monday urging ministers to make sure the gambling review does “nothing to put the industry’s competitiveness at risk”.

It describes Bet365, a gambling company, in glowing terms and praises the “huge economic contribution that the betting giant makes to our constituencies” including “high-skilled, good quality jobs” and charity donations.

“It should also not be forgotten that Bet365 and its founders are the highest taxpayers in the UK, paying some £614.6m to the Treasury in 2019/20 – money which will have helped fund vital public services like health and education, not just in Stoke-on-Trent but across the whole country,” it adds.

The politicians were not paid for their articles but the Betting and Gaming Council paid the ConservativeHome website through an advertising agency for the space online and they are labelled “sponsored”.

One of the Tory MPs, Philip Davies, MP for Shipley, wrote an article labelled “sponsored by the Betting and Gaming Council” that appeared on ConservativeHome in April. In June, he declared a ticket and hospitality box at Ascot Races with a value of £1,400 paid for by the Betting and Gaming Council, in the MPs’ register of interests.

He had no comment when approached by the Guardian. But is understood he was not paid for the article and did not realise the article was “sponsored content” when he wrote it.

Other Tory MPs who wrote sponsored content for the Betting and Gaming Council include Greg Smith, MP for Buckingham, who wrote a piece headlined “Betting shops are helping the high street get back on its feet” in June. His spokesperson said it was unpaid.

Mark Jenkinson, the MP for Workington, wrote a sponsored piece in July, saying he had “grave concerns about calls by some anti-gambling campaigners that limits should be placed on how much individuals should be allowed to bet”. Jenkinson also declared a ticket and hospitality box at Ascot Races in June, with a value of £1,400, paid for by the Betting and Gaming Council. He did not respond to requests for comment.

Brereton also did not respond to requests for comment. Bet365 is a major employer in his constituency.

Matt Zarb-Cousin, of the Campaign for Fairer Gambling, said: “Gambling reform is a very popular agenda and reforms that we and others are pushing for have overwhelming public support. You really have to question why it would be in an MP’s interest to advocate for an incredibly unpopular sector that is resisting these types of reforms.”

The government is due to publish proposals for the reform of gambling regulation early next year. Labour MP Carolyn Harris, who chairs a cross-party group examining gambling harms, has called for reform of the “national disgrace” of advertising rules around gambling.

“Until we completely overhaul their access to advertising platforms, we will continue to expose children and vulnerable adults to this unrelenting attack,” she said this week after it emerged that gambling companies are among the heaviest advertisers on radio during “school run” hours when millions of children are in cars.

A ConservativeHome spokesperson said: “Just like the Guardian, ConservativeHome carries advertising, which helps to provide high quality journalism for free to millions of readers each year.” It is understood ConservativeHome does not commission sponsored pieces but they are booked by advertisers via an agency in common with other media sources.

The Betting and Gaming Council said the MPs were not paid for the content but the body paid for the space on ConservativeHome.