Nobel Prize winning scientist Brian Schmidt, feted by Labor as an example of Australia's scientific excellence, has lashed out at Government moves to freeze research grants.

The Government has imposed what it describes as a "brief pause" on grants while it searches for extra savings to deliver its promised budget surplus.

Professor Schmidt says the decision is causing a great deal of uncertainty in the scientific community, and is warning that it could have long-term impacts.

"I have no problem with governments going through and taking a long-term view about how much they want to invest and to shape that investment over time," he told The World Today.

"But to come at the second half of a budget cycle and to do what is a pretty draconian measure of potentially freezing investment, well I think that would indicate poor planning.

"This is the type of act that makes young people - the future Nobel Prize winners, but also the future innovators of this country - leave the country and go and do their work other places."

When Professor Schmidt won the Nobel Prize for physics last year, Prime Minister Julia Gillard said it was a day on which "Aussie researchers make Australians proud".

Then innovation minister Kim Carr said at the time: "The prize illustrated Australia's great strength as a centre of scientific research excellence; a country where the spirit of discovery was valued".

Professor Schmidt says while the research that is done in Australia is very good, it's also "very fragile".

"Australia is investing more than a billion dollars a year in various forms of research, and that research is really aimed at doing things that have a 20, 30 or even 50 year horizon associated with it," he said.

"And yet when we do this uncertainty... you go through, and for a very small saving, you put a huge dent in the capacity of the nation to do this research on this 20-year timeframe.

"So $10 billion worth of investment is being put at risk for what is a saving of less than one per cent of that total investment, and that is crazy.

"Trying to save a little bit of money in the short term on what is very much a long term investment strategy in R&D (research and development) - one of the strategies to help raise productivity - is going to be counter-productive because... the damage to the overall long-term budget of the nation is going to be very large.

"Much more than what they would possibly say."

At a Senate hearing yesterday, Science and Research Minister Chris Evans rejected suggestions put forward by the Greens that the grants freeze could mean Australia lost a generation of scientists.

And he said the Government would reveal the future of the grants program when it hands down its mid-year economic update later this year.

"The Government will make a decision about each program and there will be an announcement about whether the program is fully funded, partially funded or not funded and it will be obvious to the world then," Senator Evans said.