Tam Dalyell, Labour MP for Linlithgow and long an opponent of devolution, argued that the proposals had "not been thought through'' and that the Scottish people faced a choice between the Union and independence.
The comments, which will be expanded in a speech on 17 January, will embarrass the party leader, Tony Blair, as he seeks to counter John Major's criticism of his devolution plans.
The row coincides with the emergence of the first real detail of Labour's plans for regional government in England. The Opposition is planning to set up around 10 regional bodies, on which nominated councillors from local authorities will sit.
Jack Straw, chairman of the party's democracy committee, believes the plan will avoid costly direct elections to regional assemblies. Senior party figures want the new tier to take over the regional offices of government departments which already have substantial powers over urban regeneration and training.
These government offices for the regions currently serve the North-west, Yorkshire and Humberside, the North-east, the West Midlands, the East Midlands, Merseyside, the Eastern region, the South-west, the South-east and London. Labour also plans to take quangos under the control of the new regional tier to democratise their management.
Mr Dalyell's comments, however, are likely to be seized on by the Conservatives to discredit Labour's new constitutional agenda. On 17 January, in a speech to Labour activists at Blaby, Leicestershire, the backbench MP plans to pose the same question he made famous in the late Seventies during his term as MP for West Lothian: why should a Scottish MP at Westminster be unable to vote on many Scottish matters (when power is devolved to an Edinburgh Parliament) but still vote on issues affecting England?
Last week Mr Dalyell said: "How can I, as MP for Linlithgow, vote for a sustained period of time, in perpetuity, on matters of health, education and transport in relation to Leicestershire, where I am going to speak, but not in relation to Linlithgow?''
Mr Dalyell believes that Labour is "back in 1976'' and its plan "has not been thought through''. He added that the alternatives were either the Union or independence and that "a half-way house is not stable".
The shadow Scottish Secretary, George Robertson, said yesterday: "Tam has held a long and honourable view on this but it is a fairly lonely view. The vast majority of the party is united behind this." Gordon Brown, shadow Chancellor, began the fight backagainst Mr Major yesterday, saying: "I believe the next Labour government can promise a bonfire of the quangos."
He added: "Devolution will strengthen, rather than weaken the United Kingdom.
"The devolution proposals make sense of the problems of the Scottish Office. We have no intention of allowing Mr Major to get away as being the defender of the UK.''Reuse content