Lord Sainsbury, the UK's long-standing science minister, is relinquishing his post.
He has been the Parliamentary Under-Secretary of State for Science and Innovation in Tony Blair's government since 1998.
His tenure has overseen a substantial rise in government spending on science and technology research in the UK.
His department has increased its spend in real terms from £1.3bn to what will be £3.4bn next year.
This achievement was universally recognised by leading figures in the scientific community who paid tribute on Friday to his stewardship - as well as to his commitment to the post.
"He was actually the first science minister who really wanted the job; many of the previous incumbents saw it simply as a stepping stone to a bigger portfolio or maybe they were on their way down," said Dr Peter Cotgreave, from the Campaign for Science & Engineering (Case).
"The science community came to respect him - and for the new minister to earn the same respect is going to be hard work," he told BBC News.
Professor Colin Blakemore, chief executive of the Medical Research Council, added: "He has trusted the scientific community to manage its own affairs, but has inspired a real commitment to the rapid translation of science into public benefit.
"He is hugely respected by researchers for his courage in defending science through a series of challenging public debates - particularly on stem cells and the use of animals in research."
Dr Evan Harris MP, the Liberal Democrat science spokesman, also paid tribute to Lord Sainsbury, calling him "the best thing about the government's science policy"; but he said the new minister faced a major challenge to correct some fundamental problems.
Dr Harris cited issues in education, in particular the substantial numbers of children who are still not taught science subjects by teachers with science qualifications; and the funding arrangements in higher education that have led a number of universities to close their chemistry and physics courses at degree level.
"His successor will have to sort out the crisis in school science teaching, in university science departments and in the career prospects of young scientists.
"The government's business R&D investment strategy is simply not working despite significant public subsidy, and the imposition of increased student debt on science graduates torpedoes efforts to attract the brightest and the best into public sector science and research," he added.
Lord Sainsbury is one of Britain's wealthiest individuals and a noted philanthropist; and has put a lot of money into plant biotech research.
However, this meant that because of conflict of interest rules, Lord Sainsbury could not be involved in government discussions about genetically modified crops - one of the most controversial science subjects in the public sphere in recent years.
Lord Sainsbury will keep a link with government. He will lead a nine-month Treasury review into how the development and exploitation of scientific research can be improved.
It will look at ways in which the government's £125bn procurement budget can be used to buy innovative goods and services and so create a more vibrant market for British inventions.
A rethink of procurement, particularly by the NHS in buying novel medicines and healthcare products, is something that the Bioindustries Federation has been calling for.
"Procurement across government is unfinished businesses for me," Lord Sainsbury told the BBC. "We've made a start on getting government procurement to help innovation but there is still an enormous amount to do to make that really happen on the ground as opposed to being simply just a policy."
Malcolm Wicks MP, the current energy minister, will move into the science brief
Dr Cotgreave said it was imperative that Mr Wicks "muscled in" on education matters, to ensure more science teachers came through the system and that the funding anomalies were corrected.
And he added that the new minister should also work to remove some of the "red tape" that had grown up around the government's science spend.
"Most of the new money has come with strings attached and new bureaucracy," he explained. "If that continues, that will tend to stifle the creativity of the science base to some extent, and we the public will not get the full value of that extra money."