A recommendation to cut maximum stakes on fixed odds betting terminals (FOTB) at £30 rather than £2 has been called a "cop out" by a Swansea MP.
Carolyn Harris, who runs the all-party parliamentary group for FOTB, said the machines were "as captivating as heroin" and criticised the decision.
The UK government is expected to make a decision on the Gambling Commission's advice in the coming weeks.
The Welsh Government has "strongly urged" Westminster impose a £2 cap.
People can currently bet up to £100 every 20 seconds on electronic casino games, such as roulette and blackjack, meaning gamblers can lose up to £1,500 every five minutes on a machine.
Terry White, from Barry, has lost a total of £250,000 on FOTBs and once lost £41,000 in a single day on the machines.
He said he was "worried" the changes did not go far enough and said "even at £30 a spin you can still do a lot of damage very quickly".
The Gambling Commission has advised the maximum stake be cut to £30, but Ms Harris, MP for Swansea East, said the recommendation was "disappointing".
"I think it's a bit of a cop out if I'm honest, they're covering their own backs.
"The Gambling Commissioner hasn't shown any backbone. It's really, really short sighted and taking the coward's way out.
"They have a history of not being very strong when they come up against the bookies."
The Welsh Government has also campaigned for machines to be capped at £2 per spin.
A spokesman said: "Addiction to gambling can have a serious impact on individuals and their families.
"We strongly urge the UK government to take action, resist the pressure from the industry and significantly reduce the maximum stake for category B2 gaming machines."
But the Association of British Bookmakers has claimed that a £30 maximum stake would cost the industry 10,000 jobs, and lead to 2,100 betting shops closing.
"We fully understand that there is public concern and that there will be a stake cut to reduce the levels of losses on machines in betting shops," it said after the Gambling Commission's announcement.
"In the interim, we remain committed to introducing further measures to address problem gambling and will continue to work with all interested parties."