UK bookmaker Ladbrokes Coral is set to cut £8m it spends each year on sponsoring sports as a result of the new rules being contemplated by the UK government on gaming machines.
Ladbrokes, which earns most of its income via the machines, will incur a huge loss if the government's decision comes through.
Ladbrokes currently invests £3.5m in sponsorships on horseracing events and also sponsors Rugby Football League Challenge Cup and the Scottish Professional Football League as well as snooker and darts. It was also one of the sponsor of Football Association (FA) until FA ended the sponsorship agreement in June last year.
Ladbrokes said: "A severe stake cut has many implications not least on jobs, the Treasury and the sports we support.
"Sports sponsorship is a two-way street, yes we get exposure but it also helps sports finance their entire structures right down to grass-roots funding."
Sports Minister Tracey Crouch said: "It is vital that we strike the right balance between socially responsible growth and protecting the most vulnerable, including children, from gambling-related harm.
"Given the strong evidence and public concerns about the risks of high stakes gaming machines on the high street, we are convinced of the need for action. That is why today we have set out a package of proposals to ensure all consumers and wider communities are protected."