Gambling companies and lobbyists have increased the amount they spend on MPs tenfold in five years, according to Guardian analysis that shows how the industry has become one of the best connected sectors in Westminster.

Data from publicly available parliamentary records show that dozens of Labour and Conservative MPs have received thousands of pounds’ worth of corporate hospitality in the past few years, paid for by some of the country’s biggest betting companies.

The analysis, which follows reports that the Conservative MP Scott Benton offered to lobby ministers on behalf of the industry for money, shows that the sector now spends tens of thousands of pounds a year, mainly on sports tickets for MPs. The figure is likely to be even higher than reported, as anything worth less than £300 does not have to be declared.

The figures have sparked concern among some in parliament that the gambling industry now has too much political power, especially as the government prepares to publish its gambling white paper.

Carolyn Harris, the Labour MP for Swansea East and a campaigner for more regulation of gambling, said the industry’s deep pockets and fondness for treating MPs were very obvious in and around parliament.

“If you go to the bar, you will probably see somebody from that industry, and they’re buying people drinks,” she said. “They attract people with offers to go to things that ordinary people would never get access to, like the Brits, or to watch Manchester United in the hospitality section.

“There are certain times you can have a conversation with someone from an industry, and then you go off and make an independent decision, and that’s how it works. But what happens with this industry is, why do people have to keep on being convinced so many times? Some people take the hospitality time and time again.

“They do this because they’re terrified of regulation. They have grown beyond even their own expectations, but it’s an industry where 10% of the customers make 60% of the profits. They want to protect what they have.”

Earlier this week, the Times revealed that its reporters had captured undercover footage of Benton, the MP for Blackpool South, promising to “call in favours” from colleagues and offer “easy access” to ministers in return for £4,000 from a fake gambling company.

Benton, who has been suspended from the parliamentary Conservative party and has referred himself to the parliamentary standards commissioner, is one of dozens of MPs who have accepted large amounts of corporate hospitality from the industry in recent years.

On Thursday the Times released a second video showing Benton advising the undercover reporters to list tickets as being worth just less than £300 so as to avoid having to be declared. He told them: “Without saying too much, you’d be amazed at the number of times I’ve been to races and the ticket comes to £295.”

The Guardian’s analysis shows that in 2019 the biggest gambling companies and lobbyists spent just less than £8,000 on paying for tickets to events for six MPs and their friends and families. One of the biggest recipients was the Conservative MP Laurence Robertson, who accepted thousands of pounds’ worth of tickets and hospitality from William Hill and Coral, including a day out at Doncaster races for him, his wife and a member of staff.

By 2021, however, it had risen to 25 MPs, and the industry spent £114,000.

Almost all of that went on paying for tickets and corporate hospitality at sporting and musical events for MPs. That year Benton accepted nearly £6,000 worth of tickets to racing, tennis and football events. He was one of a dozen Tory and Labour MPs who were given tickets and corporate hospitality worth nearly £3,500 each to the Euro 2020 semi-final between England and Denmark.

In 2022, the industry gave 36 MPs a total of about £87,000 worth of tickets and corporate entertainment to events, including racing, football and rugby. The Betting and Gaming Council (BGC) spent nearly £7,000 taking four MPs – including Benton and Robertson – to the Brit awards, and another £4,000 taking five MPs to an Ed Sheeran concert.

So far in 2023, the industry has spent just over £13,000 on entertaining and paying MPs – all of which has come from the BGC.

The BGC, a large and well-connected industry organisation led by the former Labour MP Michael Dugher, has increasingly become the source of the spending in the past few years, with individual companies offering less and less.

The organisation has been a powerful voice feeding into the government’s wide-ranging gambling review, which according to a report in the Sun is likely to recommend a maximum limit to how much gamblers can spend during each go on an online slot machine.

Throughout the review process, the council has pushed for a narrower definition of “gambling harm”, telling MPs on the culture, media and sport select committee: “The current debate has resulted in a large amount of misinformation around the prevalence of gambling-related harm, including by extending its definition.”

The BGC’s main voice in parliament is Laurence Robertson, who is paid £2,000 a month to act as its parliamentary adviser on sport and safer gambling. In an article on the BGC’s website, Robertson argues: “Too often it is the negative and inaccurate messages [about the betting sector] which are those heard most loudly.”

A spokesperson for the BGC said it represented an industry supporting 110,000 jobs, and as such “we routinely engage with parliamentarians – and of course we often do this in conjunction with sports like racing and football, where the betting industry has a close and historic relationship.”

It was vital for the organisation to engage with MPs amid the government review into gambling regulation, the spokesperson said, adding: “There is no suggestion of any wrongdoing whatsoever by the BGC or our members. All hospitality is declared in strict accordance with the rules.”