Tom Watson, the former Labour MP who was one of parliament’s most virulent campaigners for gambling reform, has joined the world’s largest online betting company as an adviser.

Flutter Entertainment, which owns Paddy Power, Betfair and SkyBet, said it would pay Watson a retainer, understood to be less than £100,000, to advise it on tackling problem gambling.

Watson’s appointment comes ahead of the launch later this year of a government review of gambling law, which could result in sweeping changes to the regulation of the industry.

“I have a longstanding interest in this sector and have consistently called for action to protect those who may be potentially vulnerable to harm,” said Watson. “In taking on this role in Flutter, I intend to get under the bonnet of the business – and the industry more widely – to understand how best to further develop and implement industry-leading responsible gambling policies.

“I strongly believe that working collaboratively with Flutter in this way will allow me to continue to drive positive change.”

Matt Zarb-Cousin, who runs the Clean Up Gambling campaign group and was also an adviser to Jeremy Corbyn when Watson was Labour deputy leader, said: “We hope Flutter doesn’t stand in the way of the reforms their new adviser once proposed.”

The role with Flutter, first reported by the Financial Times, is not the first post Watson has taken in the private sector since leaving Westminster. He also became chairman of UK Music, where his close friend and fellow former Labour MP Michael Dugher was chief executive until he left to lead the Betting & Gaming Council, which lobbies on behalf of bookmakers and online casinos.

As Labour’s deputy leader, Watson led a review that saw the party reverse the stance taken under the leadership of Tony Blair, whose government introduced the 2005 Gambling Act that introduced some of the world’s loosest gambling laws.

He was the driving force behind party policies such as a mandatory levy on the industry and banning betting company logos on football shirts.

Paddy Power, one of the leading brands owned by Watson’s new employer, has since been criticised over a stunt for which the football team Huddersfield Town was fined £50,000 for wearing the company’s logo in a one-off friendly match.

A former aide to Watson said they believed he was taking the job with the genuine intention of influencing the industry to behave better. “I don’t think he would have taken it if he didn’t think he could do some good,” they said.