The Bank of England has unveiled its first plastic banknote, featuring World War II leader Winston Churchill and giving campaigners in Britain's European Union referendum an opportunity to renew their skirmishes.
The central bank said in 2013 that Mr Churchill would appear on its next five-pound banknote, which will be the first to be made from a very thin plastic.
The BoE said the polymer notes will be more durable and harder to forge than paper ones.
"By adopting polymer, we're aligning with international best practice, alongside Australia, New Zealand, and Canada," BoE governor Mark Carney said on Thursday.
"As Churchill did, we may have to wait a while for the Americans to join up," he said, alluding to the United States entering the war in 1941, more than two years after Britain.
Mr Carney was speaking as the Bank showed off its final design for the new note at Mr Churchill's birthplace, the 18th-century Blenheim Palace, eight miles north of Oxford.
Inevitably, the appearance of Mr Churchill on the notes was seized upon by campaigners ahead of the June 23 EU referendum.
Veterans for Britain, a group representing former service personnel which wants a so-called Brexit, pressed its claim that the wartime prime minister saw Britain as friendly towards a developing union in Europe after the war, but separate to it.
"It's wonderful that Churchill is on the fiver - it will remind people to put the country's interests first on June 23," Andrew Roberts, a history professor at Kings College London, said in a statement sent to media by the group.
Rival campaigners who want to keep Britain in the EU have also previously invoked Mr Churchill.
Prime Minister David Cameron said last month that his predecessor's legacy showed that "isolationism has never served this country well".
A new plastic 10-pound note featuring the author of Pride and Prejudice, Jane Austen, will appear in 2017 and 19th century artist J.M.W. Turner, most famous for his seascapes, is due to feature on a plastic 20-pound note from 2020.
Mr Churchill replaces 19th-century prison reformer Elizabeth Fry, who has appeared on the five pound note since 2001.