Boris Johnson has apparently backed the use of real black bear fur for hats worn by the Queen's Guard.
In a leaked email, sent to a constituent in December, the Prime Minister suggested bearskins would continue to be used by the Ministry of Defence (MOD), in part, because they look better.
Mr Johnson noted People for the Ethical Treatment of Animals (PETA) had commissioned a man-made alternative to the material used to make the ceremonial caps.
But he wrote that while it met the "basic standard for water absorption", it "showed unacceptable rates of water shedding and performed poorly on visual assessment."
He added: "Sadly, as the man-made fur did not meet the standards required for a ceremonial cap which is worn throughout the year and in all weathers, the Ministry of Defence has no plans at present to take the man-made fabric forward. However, all these matters are kept under review."
The email,
, thanked the constituent - a former armed forces member - for their service to the country.
PETA last year named Mr Johnson's wife Carrie - a passionate campaigner for animal rights - their "person of the year."
But the pressure group told LBC black bears "shouldn't be slaughtered for ornamental hats."
In 2020, the MoD spent £145,000 on pelts from Canada.
That's enough for 110 hats at a cost of £1,315 each.
In response to a complaint about the use of real fur in December, the MoD wrote that the man-made fabric lost its shape, and was poor at keeping the rain off soldiers' heads.
Number 10 has been approached for comment.
