Peter Hain was last night accused of setting up Wales for a constitutional crisis over the controversial issue of proportional representation.

The Welsh Secretary suggested MPs would veto any future non- Labour Assembly Government's plans to change the voting system for councils.

Mr Hain indicated that if the present opposition parties formed a coalition administration after next May's election, MPs at Westminster would not necessarily agree to their legislative plans.

Asked whether a non-Labour coalition would be allowed to introduce proportional representation in council elections, Mr Hain said, 'The policy of Welsh Labour, adopted unanimously at our special conference on Saturday, is emphatic. Welsh Labour will not consider and would never accept any move towards PR in local government in Wales.'

Mr Hain added, 'The people of Wales deserve an honest choice. We in Welsh Labour will be fighting next May's elections on a full policy programme, and if our opponents want to form a government, they must do the same. 'The people of Wales deserve better than shady backroom deals struck by a ragtag Tory-led coalition whose policies do not add up.'

A source close to Mr Hain confirmed that any move towards PR in local government was likely to be blocked by Welsh Labour MPs during pre-legislative scrutiny at Westminster.

The source said it would be difficult for any non-Labour coalition to claim that PR was an issue that resonated with the Welsh electorate.

Both Mr Hain and First Minister Rhodri Morgan have emphatically rejected PR in local government, thus effectively ruling out any chance of a coalition with the Liberal Democrats if Labour fails to win an overall majority next May.

Plaid Cymru leader Ieuan Wyn Jones said, 'This statement from Peter Hain shows he is prepared to defy the electoral mandate given to the next Assembly Government by the people of Wales. He is setting himself up for a constitutional crisis.

'This shows the arrogance of the Labour party. The Labour party has boasted about the new powers the Assembly will receive next year, but the Secretary of State's comments will make a mockery of the process and undermine democracy if the wishes of the Welsh Assembly are to be ignored in this way.

'It would be an utter disgrace if Labour MPs blocked the will of the Welsh Assembly because they do not agree with the policies of the Governing party. The Assembly should be free to make its own decisions - the whole point of devolution is to give the people of Wales more power - the flexing of Westminster muscle in this way harks back to the days of Redwood and a Tory-controlled Welsh Office - it wasn't acceptable then, and it isn't acceptable now.'

Welsh Conservative leader Nick Bourne said, 'While I am not necessarily sold on the idea of PR in local government, Peter Hain's approach is high-handed and colonial. Perhaps he is mixing up his role in Northern Ireland, where he has been operating in a political vacuum, with his role in Wales, where there most definitely is not a vacuum.

'Peter Hain has been posing as a supporter of extending the powers of the Assembly, but it is now clear that he will only support measures that suit the narrow interests of his party.

'This is undemocratic and makes a nonsense of his supposed commitment to devolution.

'I have always taken the view that the changes coming in next May could lead to a feast or a famine for the Assembly, depending on the views of whoever the Secretary of State may be. Perhaps we should hope Peter Hain becomes Deputy Leader of the Labour Party and that someone with a greater commitment to democracy takes over as Secretary of State.'

Welsh Liberal Democrat leader Mike German said, 'I fully expect Labour at this stage to be saying they won't support PR for local government. If they have a majority, of course it won't happen. But most observers expect them to lose seats, rather than gain them, and Labour haven't woken up to that reality. So far, they've avoided telling us what they'll do when they fail to get a majority.

'Labour MPs need to realise they won't be asked the question about PR for local government. They will only be asked whether or not to transfer powers to the Assembly over local government elections.

'If Labour are really saying that they will block bids for extra powers because they don't like how they might be used, then what's the point of devolution? If their MPs are saying they won't give the Assembly the freedom to deliver the manifestos of governing parties, then I think the people of Wales will take a dim view of that. No one likes a bully, and a party showing such a dictatorial streak would become even more unpopular.

'Let's be clear - there's no philosophical objection to PR in the Labour Party. Labour introduced it for Assembly elections and the European elections. Labour has introduced PR to local government in Scotland. Elections in Northern Ireland (except for Parliament) are done this way. What we've seen is just macho posturing.'