Chancellor Rishi Sunak has pledged to more than double spending on UK government research and development (R&D) by 2024.
Mr Sunak promised an increase of 15% for next year with further increases in successive years.
The pledge means that the government may exceed its target of boosting the proportion of private and public R&D spend from 1.7% to 2.4% by 2027.
The chief scientific adviser, Patrick Vallance, welcomed the announcement.
"This significant increase in funding for research and development represents an overwhelming endorsement of our world-leading science base," he said.
"It puts the UK in an excellent position to lead the field in science and successfully meet the challenges of the future."
The budget document states that the total proposed investment will represent 0.8% of GDP in 2024/25.
If industry boosts its investment by the same amount, Dr Sarah Main of the Campaign for Science and Engineering (Case) says that its projections indicate that the government will exceed its 2.4% goal by the target date.
"This is a 'wow' moment for us," Dr Main told BBC News.
"The government has supercharged public investment in science, delivering investment faster and further than it had promised."
How the money will be spent
The Prime Minister's chief adviser Dominic Cummings has been in discussions with scientific leaders about how the doubling of the science budget should be best spent. I understand that a proportion of it will go to make up for the real-terms cut that some research areas have faced in recent years.
But the bulk will go towards luring money from the private sector to get industry to spend more on research. Currently, industrial R&D accounts for two-thirds of the country's non-defence research spend - with the remainder coming mostly from government.
If the UK is to approach the funding levels of the US, Germany and South Korea, industry has to step up and double its R&D, too.
The thinking is to solve the age-old problem of the UK failing to turn its world-class science into world-class goods and services that create jobs and benefit the economy.
Successive governments have tried and failed to do this for decades. I put this point to a senior official drawing up the new plan. Their response was: "They didn't have the kind of money we have now."
Details of how the extra money will be spent will be unveiled in the spending review later this year.
But the Chancellor said that £800m would be available for a new research body based on a former US government agency called Arpa (the Advanced Research Projects Agency) - now known as Darpa.
British Arpa, as it has been dubbed, is backed by Dominic Cummings. It would fund ambitious proposals in emerging fields with a high risk of failure but great potential. The president of the UK's Royal Society, Prof Sir Venki Ramakrishnan, said that the investment demonstrated the government was prepared to try new things.
"We must also continue to build on our great strengths in the basic research that feeds the innovation of the future and will ensure the UK maintains its status as a global science leader," he said.
There was also a commitment to distribute the new funding to universities outside London, Oxford and Cambridge.
Prof Sir Robert Lechler, president of The Academy of Medical Sciences, said he was delighted by the announcement.
"The measures set out by the Chancellor show that this government is serious about its promises to double our investment in research," he commented.
"This increase in funding has the potential to transform our capacity in medical research and our ability to address major health and societal challenges."
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