Gambling liberalisation introduced by the former Labour government was a "mistake" and has ruined people's lives, the party's deputy leader Harriet Harman has admitted.
Ms Harman called for action to reverse measures in the Gambling Act which allowed the proliferation of betting shops in poor areas, many of them operating high-stakes roulette terminals.
Research conducted for Channel 4's Dispatches suggested that British punters lost well over £1 billion last year on the Fixed-Odds Betting Terminals (FOBT machines), which allow bets of up to £100 every 30 seconds on touch-screen roulette games.
FOBT machines first appeared in the UK in 2001 and the 2005 Act introduced a limit of four for each betting shop in England and Wales. But a parliamentary report by the House of Commons Culture Committee last month recommended lifting the limit, which it said has had the "unintended consequence of encouraging the clustering of betting shops in some high streets".
Research for Dispatches suggested that relatively prosperous areas have around five bookies for every 100,000 people, while poorer areas have about 12 - with some high streets in deprived neighbourhoods seeing a cluster of 10 betting shops within a mile, each containing four FOBT machines.
Professor Jim Orford from Birmingham University told Dispatches that an estimated £297 million of the money taken by FOBT machines each year comes from problem gamblers, whose habit is damaging their relationships and careers.
"Getting on for a quarter of all the profits from these machines are being contributed we think by people who've got problems with their gambling," said Prof Orford. "My own view is that we should probably get rid of them on the high street. I don't think casino gaming by machine belongs in the high street, I think it belongs in casinos."
Ms Harman told the programme: "If we had known then what we know now (about the clustering of betting shops), we wouldn't have allowed this, because it's not just ruining the high street, it's ruining people's lives.
"I got the most heart-rending letters and emails and calls that I've ever had in 30 years of being an MP, just saying 'Please do something about this. It's ruined my life, it's ruined my family, it's really dangerous and the problem is it's getting worse and that's why we need the law to be changed so that something can be done about it'.
"Well, I think we were wrong, we have made a mistake and this result is the consequence and we need to do something about it."