The Archbishop of Canterbury cast a crucial vote last night when he turned up with other bishops in the House of Lords to speak against the government’s proposals for a supercasino in Manchester – which were defeated by just three votes.

It was the first time he has spoken or voted in the Second Chamber since May last year, and will heat up the debate about the place of unelected bishops in Parliament.

The votes of the three bishops proved decisive in defeating the government.

The Archbishop of Canterbury Rowan Williams, the bishop of Peterborough and the bishop of Southwell and Nottingham were the only bishops to vote of the 26 who sit in the House of Lords.

They all backed the amendment by Liberal Democrat Lord Clement-Jones declining to approve the Gambling Order and calling for a joint committee of the Lords and the Commons to look again at the decision-making process surrounding the proposed supercasino.

The fact that the votes of the unelected members of the House of Lords were so decisive is bound to heat up the debate about whether bishops should lose their privileged status and be excluded from a reformed House of Lords.

The House of Commons recently voted for a 100% elected Second Chamber.

Although campaigns against the supercasinos have been led by the Methodist Church, former leader of the Methodist Conference Leslie Griffiths, who was appointed to the House of Lords as a Labour Peer Lord Griffiths of Burry Port in 2004, did not vote last night.

Speaking in the House of Lords for the first time since May last year, Rowan Williams said of the government’s plans for a supercasino in Manchester: “Sadly, the general impression that has been given is of a piece of inadequately monitored social experimentation.

“My general grounds for unease do not rest primarily on a principled opposition to all forms of gambling in any shape in any place. Belonging to a church which has a mixed record on these matters, I can hardly take the moral ground with too much confidence. My objection is rather to the sleight of hand by which the whole business of the gambling industry has become coupled with the regeneration theme in ways which—I have to be candid—I find quite baffling.”

“We have been reminded already by several noble Lords that terms such as problem gambling conceal a rather more unpalatable and extreme reality, of which some have spoken, in terms of addictive behaviour. While it is undoubtedly true statistically that casino gambling represents a relatively small segment of the overall problem of addictive gambling, none the less it represents a significant part and a social factor whose impact on its immediate environment is not restricted to addictive gambling”, he said.

A list of all those voting last night and the full text of the debate can be found here