The polymer £50 note will be issued for the first time on 23 June 2021, which coincides with Turing’s birthday. The note contains advanced security features, completing the bank’s most secure set of polymer banknotes yet.

The note, like the £20 note featuring artist JMW Turner which entered circulation in February 2020, incorporates two windows and a two-colour foil, making it very difficult to counterfeit.

There is also a hologram image which changes between the words ‘Fifty’ and ‘Pounds’ when tilting the note from side to side. It will also feature the signature of Sarah John, the bank’s chief cashier.

The Bank of England says one of the benefits shared by all its polymer banknotes is that they last longer than paper notes and stay in better condition during their use.

The new £50 note, like the polymer £10 and £20 will contain a tactile feature to help vision impaired people identify the denomination.

The polymer £50 note will join the Churchill £5, the Austen £10 and the Turner £20, meaning all Bank of England banknotes are now available in polymer.

The public will begin to see the new £50 from 23 June 2021 as the notes enter general circulation. The public can continue to use paper £50 notes as usual. Notice will be given at least six months ahead of the date when the old paper £50 is withdrawn.

Andrew Bailey, governor of the Bank of England, said: “There’s something of the character of a nation in its money, and we are right to consider and celebrate the people on our banknotes. So, I’m delighted that our new £50 features one of Britain’s most important scientists, Alan Turing.

“Turing is best known for his codebreaking work at Bletchley Park, which helped end the Second World War. However, in addition he was a leading mathematician, developmental biologist, and a pioneer in the field of computer science. He was also gay, and was treated appallingly as a result. By placing him on our new polymer £50 banknote, we are celebrating his achievements, and the values he symbolises.”

Jeremy Fleming, director of GCHQ, said: “Alan Turing’s appearance on the £50 note is a landmark moment in our history. Not only is it a celebration of his scientific genius which helped to shorten the war and influence the technology we still use today, it also confirms his status as one of the most iconic LGBT+ figures in the world.

“Turing was embraced for his brilliance and persecuted for being gay. His legacy is a reminder of the value of embracing all aspects of diversity, but also the work we still need to do to become truly inclusive.”