Dr Jeremy Bray, who has died aged 71, had a political career in the Labour Party which spanned more than 30 years. Much of it was spent as MP for Motherwell. He was also a distinguished

scientist and a mathematician.

Dr Bray first won the Motherwell and Wishaw seat in 1974 and stood down voluntarily at the 1997 general election. Previously he had represented Middlesbrough West from 1962 to 1970.

Colleagues and fellow campaigners paid tribute to the valiant fight he put up, with other Lanarkshire MPs, to try to halt the closure of the Ravenscraig steel works a decade ago and to save what was left of the Scottish steel industry.

Dr Bray was in the thick of the ultimately unsuccessful campaign at Westminster and in Lanarkshire to stop British Steel closing the plant. On the last day of production in June 1992, he once again raised the issue in the House of Commons.

After paying a tribute to the skills and dedication of the workers, he urged Tory ministers to accelerate the reclamation and development programme in

the area.

Frank Roy, his one-time election agent and eventual successor in the Motherwell seat, said yesterday: ''During the Ravenscraig crisis, Jeremy left his sick bed to come and debate and fight for the jobs of the steelworkers there. Although the battle was lost, there was great admiration and respect for his tireless struggle to try and save the plant.''

Tommy Brennan, who was convener of shop stewards at Ravenscraig for 16 years, said the former MP was a ''man for whom I have great affection and respect. He was totally committed to the retention of Ravenscraig''.

He remembers a highly educated man who had the common touch and ''a tremendous belly laugh'' - a man who used to meet the shop stewards off the train in London and make sure they had a good breakfast before a day of lobbying at Westminster. Helen Liddell, the Scottish secretary, paid her own tribute yesterday. ''Jeremy was a very distinguished scientist who brought his expertise and commitment to his work as an MP. He ably represented the people of Motherwell for a great number of years. My thoughts are with his family.''

Jack McConnell, the first minister, said ''His reputation as a representative for Motherwell and Wishaw in parliament was first class and there are many fond memories locally of

Jeremy Bray.''

Jeremy William Bray was born in Hong Kong in 1930. The son of a minister, he was educated at Aberystwyth Grammar School, and later went to Jesus College Cambridge where he researched in pure mathematics and received a PhD in 1956.

He worked as a statistician for ICI before becoming Labour MP for Middlesbrough West in 1962. Tam Dalyell, Labour MP for Linlithgow, a close friend, who started his Westminster career on the same day, recalls an intellectually dazzling debut.

Mr Dalyell said Bray's 25-minute maiden speech put forward his proposal for a complicated new clause in a finance bill - ''annual allowances on increases of stocks of proscribed goods''. Afterwards there was high praise for his contribution from both the Tory and

Labour benches.

Mr Dalyell added: ''The idea, though typically complex, was of great help to the steel industry on Tees-side and it was no wonder, given the problems of Ravenscraig and Jeremy Bray's record of expertise in the steel and chemical industry, that Motherwell chose him as MP.''

Bray's talents were quickly recognised and he served as junior minister in the departments of power and technology during Harold Wilson's governments in the 1960s.

In 1969 he resigned his post when the prime minister, following established practice, refused to allow him permission to publish a book dealing with current decision-making processes in

the government.

At the time, Dr Bray said he understood the reasons for Mr Wilson's stance and said there was no disagreement on policy.

After a lengthy quotation from Milton, warning we should be wary of ''what persecution we raise against the living labours of publick men'', his resignation letter went on: ''A party of change which is also a party of government, must look fearlessly at the lessons of experience and be able to renew its sense of direction and revitalise its mission while

in office.''

Dr Bray was a research fellow at Strathclyde University and living in Helensburgh when, in 1974, he was chosen as Labour's candidate for Motherwell and Wishaw, one of the safest seats

in Scotland.

A decade later in 1985, left- wing activists made an unsuccessful attempt to oust him while he was serving as opposition spokesman on science and

technology. In 1990 Dr Bray underwent a major heart operation but quickly resumed his parliamentary duties as the situation over the future of the Scottish steel industry reached crisis point.

He died at his home in Cambridge after a long illness and is survived by his wife, Elizabeth, whom he married in 1953, and four daughters.

Jeremy Bray, scientist and politician; born June 29, 1930, died May 31, 2002.