At least 2bn polymer notes are to be rolled out across the country from Thursday

The new polymer £20 note featuring the artist JMW Turner is to go into circulation, as the Bank of England begins a mammoth operation to replace the most popular banknote in the country.

At least 2bn have been printed, and the Bank expects half of the country’s cash machines to have switched over within the next fortnight.

In Scotland, Bank of Scotland and Clydesdale will launch their polymer £20 notes on 27 February, with Royal Bank of Scotland following on 5 March. Banks in Northern Ireland will also change over in 2020, but there is no specific date.

Judging by the huge popularity of earlier polymer note issues, the Bank of England said it expected to see queues outside its Threadneedle Street head office when it opened its doors at 9am.

Not all bank branches will be stocking the new £20 immediately. For example, Santander said only 12 of its branches would have the new note from Thursday. They include branches in Birmingham, Cardiff and Leeds.

The note will feature Turner’s portrait in front of The Fighting Temeraire, his tribute to the ship that played a distinguished role in Nelson’s victory at the Battle of Trafalgar in 1805. It will also be the first note to include the signature of Sarah John, the Bank of England’s chief cashier since 2018.

The Bank of England governor, Mark Carney, chose Tate Britain, which is home to the most important Turner collection, to launch the new note. The Fighting Temeraire, which is currently in the National Gallery, will be on view at Tate Britain in the autumn for a major Turner exhibition.

He said: “I am delighted that the work of arguably the single most influential British artist of all time will now appear on another 2bn works of art – the new £20 notes that people can start using today.”

The Bank said the banknote will be the single biggest switchover to polymer attempted anywhere in the world. While first adopted by Australia in 1988, US dollars and euros have so far resisted the switch to plastic.

According to the Bank of England, if the new £20 notes were laid end to end, they would stretch around the world almost seven times and weigh a total of 1,780 tonnes. The notes are manufactured in England by De La Rue.

Unlike the launch of the polymer £5 and £10 notes, Britain’s central bank has not set a date for when the older paper-cotton notes will stop being legal tender, so they can continue to be used in circulation. It said it will give at least six months’ notice of any withdrawal date.

The Bank is opting for polymer over traditional paper because it is cleaner, longer-lasting and harder to forge.

Facebook Twitter Pinterest The new £20 note in front of Turner’s The Fighting Temeraire at the National Gallery in London. Photograph: Snapchat/PA

Old notes removed from circulation are either turned into compost, or burned to generate electricity.

Despite the fact that non-polymer £5 and £10 notes are no longer legal tender, £1.5bn worth are still in existence. The Bank of England said as of July 2019, there were 118m old £5 notes and 93.8m £10 notes that had not been returned.

But individuals have the right in perpetuity to bring old notes to the Bank of England and swap them for a new note of the same value.

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Unlike in the eurozone, where the €50 is the most common note in circulation, the British have traditionally preferred lower denominations.

There are about 2bn paper £20 notes in circulation, compared with 1.1bn £10 notes, 400m £5 notes and 350m £50 notes.

Despite the decline in the use of cash, the total value of notes in circulation has remained broadly static in recent years. The Bank said it had found that while people were carrying the same amount of cash as before, it stayed longer in purses and wallets than before before being spent.