Two 50p Brexit coins minted with the wrong exit date discovered and are said to be worth tens of thousands of pounds

People are being urged to check their pockets after two 50p Brexit coins minted with the wrong exit date were discovered.

Two 50p Brexit coins minted with the wrong exit date have been discovered - and they could be worth tens of thousands of pounds.

The coins were meant to mark Brexit day on 31 October 2019, but then prime minister Boris Johnson was forced to seek an extension by Parliament.

Around a million of the coins were melted down and recycled after the new Brexit day was set for 31 January 2020.

But two of the coins survived the process and have now surfaced at Spink & Son auction house.

The coins are said to be the only two remaining in circulation, despite a Royal Mint spokesman saying they were unable to confirm the validity of the coins.

Numismatic specialist Gregory Edmund, from Spink & Son, told The Telegraph: “Ever since the official London Gazette notice for the 2019 Brexit 50 pence has existed, I have wondered if survivors of the one million cancelled coins would one day surface.

“Given the extremely stringent security at the Royal Mint, to suddenly have two examples survive, and be available for study at the same time, is a unique opportunity.

“This truly feels like my Charlie Bucket moment discovering the numismatic Golden Ticket.”

A thousand trial coins had also been made to mark the first exit date of March 29 2019, which was missed by Mr Johnson’s predecessor Theresa May.

Mr Edmund said that if the coins went up for auction he would expect them to fetch more than £40,000.

He has set up a hotline for people who have found another one of the rare coins to come forward.

At the time they were put into circulation, the Brexit coins sparked controversy before entering circulation – and not just for political reasons.

Their inscription reads: “Peace, prosperity and friendship with all nations.”

Author Sir Philip Pullman called for the coins to be boycotted for not having an Oxford comma and wrote on Twitter that the omission meant the coin should “be boycotted by all literate people”.

An Oxford comma is used after the penultimate item in a list of three or more items, so would be placed after the word “prosperity”.