Tom Watson, Labour’s former deputy leader, has been appointed as an adviser to Flutter, which owns brands like Paddy Power and Betfair.
Mr Watson was a vocal anti-gambling campaigner during his time as an MP, which ended last year when he left Parliament.
He told the Financial Times that his role at Flutter would allow him to “jump in at the deep end of the company, learn how they operate and let me share my unvarnished thoughts about what they do”.
The firm, which also owns Sky Bet and Poker Stars, said Mr Watson will “bring a fresh and robust voice into the business, as it looks for ways to protect vulnerable customers” and he will be “immersing himself” in all areas of the business.
CEO Peter Jackson said: “Bringing in someone with Tom’s gambling reform background is an important part of my commitment to lead the industry’s race to the top.
“Tom will hold a mirror up to help us make sure we are getting this balance right, and I welcome the opportunity to work with him and hear what he has to say in coming months.”
Mr Watson previously called for an end to gambling advertising on football shirts and a ban on TV ads during live events. He criticised it as a “hidden epidemic”.
After he resigned from his West Bromwich East seat, following attempts by allies of former Labour leader Jeremy Corbyn to remove him as deputy leader, Mr Watson announced he wanted a change of career and was retraining as a gym instructor.
He was also recently appointed as chair of trade body UK Music, which was opposed by representatives of the country’s biggest record labels who complained he lacked sufficient knowledge of the music industry.
UK Music defended his appointment, pointing out Mr Watson had been Shadow Culture Secretary for over three years before he stood down in Parliament and he supported the reform of live music licensing and fair ticketing.