Prime Minister Julia Gillard has appeared to confirm reports that a planned $400 million cut from medical research has been scrapped.

The rumoured budget cuts had sparked an advertising campaign and demonstrations by health researchers in several of Australia's capital cities.

Describing the cuts as "speculation", Ms Gillard appeared to reassure the sector this morning, telling researchers to wait and see.

"For those who have reacted and even gone out and demonstrated because of their concerns, I'd say the moment to judge is on budget night," she said.

"There's never been more money invested in medical research in this nation's history than there is today, right now, under this Government."

Professor Julio Licinio, director of the John Curtin School of Medical Research and a prime mover of the campaign to maintain funding, says he is delighted with the news.

But he says the campaign will continue.

"I think it's very important to continue to develop the momentum and continue the campaign so in the future people don't think of medical research as something that can be put in the general pool to be cut," Professor Licinio told ABC News Online.