The high profile scientist Baroness Greenfield has not been put on the shortlist to be a fellow of the Royal Society, the UK's science academy.
Baroness Greenfield: A champion for science
The Oxford professor of physiology is the first female director of the Royal Institution and a champion of science in her frequent media appearances.
But it is reported that some unnamed current fellows have doubted the value of her contribution to science.
Professor Greenfield said she was surprised the issue had become public.
"I don't understand how or why my nomination has been made public," she said in a statement.
"I think it is a great pity that those who do not have the courage to identify themselves can make unsubstantiated criticisms both of my science and of my activities in public communication."
Dr Ian Gibson MP, who chairs the Commons Science and Technology Committee, said he was surprised a scientist of the stature of Professor Greenfield had not made it on to the final list of candidates for election.
"She certainly has a high profile which is very important for the profile of science in the UK and in the world. She publishes papers in high-flying journals; she runs the Royal Institution and has open events in the evening," he told the BBC.
He said it was important that public bodies like the Royal Society had open criteria so it could be seen whether the very many excellent women scientists in the UK were being given a fair opportunity to become fellows.
Stephen Cox, the executive secretary of the Royal Society, said the election process was long, rigorous and peer reviewed.
He denied Professor Greenfield's media work had counted against her in any way.
"The criterion is scientific excellence," he said. "Forty-four names will come out of this election process, out of 500 people who were nominated. Mathematics tells you a great many of them are not going to make it."
A fellowship to the Royal Society is one of the highest honours a scientist can receive. Past fellows have included Isaac Newton, Albert Einstein and Charles Darwin. Present fellows include Richard Dawkins and Stephen Hawking.
Baroness Greenfield is a brain scientist who became a "people's peer" in 2001. The magazines and tabloids have enjoyed her "mini-skirted boffin" image whilst she has revelled in taking the scientific establishment to task over its "institutional sexism".
Her appearances on TV and radio popularising science have brought her many admirers, though - and a clutch of other awards, including the Royal Society's own Faraday medal which is given for excellence in communicating science.