LONDON – The Bank of England has decided to honor a scientist with its next bank note design. One of the nominees? Margaret Thatcher, Britain's first female prime minister.

Thatcher held power for more than a decade from 1979, reshaping British politics. But she appears on the central bank's list of 800 names because of her time as a research chemist at a food company in the late 1940s, playing a disputed but much-discussed role in the history of ice cream.

The bank plans to introduce a new 50-pound note — the largest and rarest of its regular denominations, worth about $64 — in 2020, as part of a program replacing paper bills with sturdier polymer versions. Its bills feature Queen Elizabeth on one side and a historical figure on the other; the current 50-pound note has James Watt and Matthew Boulton, pioneers of the steam engine.

Nominations for a replacement are open until Dec. 14, but the bank published the suggestions that had met its basic criteria so far. "We have reviewed each 'unique nomination' to assess whether they are a real person, deceased and whether they have contributed to the field of science in the U.K. in any way," a spokesman for the Bank of England said.

Other nominees include Alan Turing, the mathematician who played a key role in inventing modern computing, and Alexander Fleming, who discovered penicillin.

In the case of Thatcher, the bank's statement added, the scientific contribution was "famously working on the research team which helped invent soft-scoop ice cream."

Thatcher, then Margaret Hilda Roberts, studied chemistry at the University of Oxford, and, after graduating, worked as a chemist at J. Lyons, a British restaurant chain that also sold its own lines of food and, for a while, some of the world's first business computers.

The invention claim has been widely distributed, even appearing in the address given at Thatcher's funeral in 2013 by the then-bishop of London, who described her as "part of the team that invented Mr. Whippy," the major British soft-serve brand.

Charles Moore, her biographer, is skeptical even while noting that "she was quite a good chemist as a student at Oxford; she was a serious chemist."

She worked at J. Lyons for about 18 months, he said. Of the soft-serve claim, he added: "I've never been able to establish that it's definitely true."

An article on her scientific career in "Notes and Records of the Royal Society," a history-of-science journal, suggests that the idea of her inventing soft-serve appealed to "British left circles," who thought it fitting that a future free-market prime minister should have been involved in a product that "added air, lowered quality and raised profits."

"Whatever she did, it wouldn't be very important because it was a junior job," Moore said, adding that she had already decided to become a politician.