Critics fear the changes could produce a rise in problem gambling

They joined other politicians and church leaders angry at proposals to remove casino restrictions and allow slot machines with unlimited prizes.

The MPs included Denzil Davies, Jon Owen Jones, Win Griffiths, Betty Williams and Llew Smith.

Culture Secretary Tessa Jowell has acknowledged MPs' concerns and said she was open to constructive suggestions.

The Roman Catholic Archbishop of Cardiff, the Most Reverend Peter Smith, was among five clergymen who sent a letter of protest to the Daily Telegraph on Monday, urging caution.

The thought of casinos being given planning consent in return for various bribes to the community fills me with dread Wayne David MP

While they supported the new safeguards in the bill, they warned that it "paves the way for huge casinos that will contain some of the most addictive forms of gambling."

They added: "The knock-on effects of problem gambling, including family and relationship breakdown, are severe and harmful.

"Ruined lives are not a price worth paying for more gambling opportunities."

GAMBLING BILL Casinos open 24 hours Immediate access for public, no 24-hour joining period Unlimited jackpots in largest casinos Betting allowed on Good Friday and Christmas Day A new criminal offence of inviting, permitting or causing a child to gamble Compulsory age checks by gambling websites operating from the UK Mystery shopper surveys by the Gambling Commission to check rules followed Tighter restrictions on betting exchanges Allowing casinos to advertise for first time What the papers say

Mr Smith told the BBC's Wales Today: "To put these things in Wales would be an absolute disaster.

"For people who are out of work and have limited leisure activities, they will be a huge draw."

The letter echoed the views of the Archbishop of Canterbury, - and former Anglican Archbishop of Wales - Dr Rowan Williams, who said the new bill could endanger the vulnerable.

Dr Williams has met senior ministers to voice his concerns that a proliferation of "super casinos" would increase debt and problem gambling.

The bill passed its second reading in the Commons on Monday, despite opposition from Conservative, Liberal Democrat, Plaid Cymru and Labour MPs.

Ms Jowell has said that 90% of the bill covered tougher regulation, and problem gambling would increase if the law did not change.

She also said it would ensure the removal of slot machines from places where children can get hooked on them. But she said there had been a "massive backlash" to the proposals and promised more research on gambling addiction.

Applications have already been made for "super casinos" in Cardiff and Bridgend, and in Swansea, 500 jobs have been promised when a �30m entertainment complex opens in the city centre.

The Archbishop of Cardiff calls 'super casinos' a disaster

"There is a huge contradiction at the heart of this bill," said Mr David, MP for Caerphilly.

"It includes measures to protect children and vulnerable people but, at the same time, it deliberately encourages a massive increase in harder forms of gambling.

"I want to see a bill that offers comprehensive protection - not one that results in an increase in problem gambling.

Mr David said he had doubts about whether large casinos could be used to help economic regeneration for poorer areas of Wales.

He said of his own constituency: "The thought of casinos being given planning consent in return for various bribes to the community fills me with dread."

Plaid Cymru Ceredigion MP Simon Thomas said the bill failed to give local councils enough powers to "resist the might of American casino companies".

Mr Thomas said: "On the one hand the government wants to tighten regulation by doing away with perfectly innocent slot machines located in seaside resorts, and on the other, it proposes allowing the number of very large Las Vegas-style casinos to increase considerably.

"If the government genuinely wants to regulate gambling and protect the young, it should look more closely at the rapidly expanding internet gambling industry which is a potential minefield."