Prime Minister Rishi Sunak has said that Nike “should not mess” with the St George’s Cross, as he waded into a row over the brand’s decision to change the flag’s colour on its new England shirt.

It comes after Nike revealed it had altered the cross using purple and blue horizontal stripes in what it called a “playful update” to the shirt ahead of Euro 2024.

The US firm said the colours were inspired by the training kit worn by England’s 1966 World Cup winners.

Mr Sunak’s comments echo those of Labour leader Sir Keir Starmer, who said the flag was a “unifier”.

Speaking to reporters in Heanor, Derbyshire, the Prime Minister said: “Obviously I prefer the original, and my general view is that when it comes to our national flags, we shouldn’t mess with them.

“Because they are a source of pride, identity, who we are, and they’re perfect as they are.”

Sir Keir went even further than the Prime Minister, calling for the sporting brand to “reconsider” the decision to modify it.

He told The Sun: “I’m a big football fan, I go to England games, men and women’s games, and the flag is used by everybody. It is a unifier. It doesn’t need to be changed. We just need to be proud of it.

“So, I think they should just reconsider this and change it back. I’m not even sure they can properly explain why they thought they needed to change it in the first place.”

A petition on Change.org calling for a design change had already attracted more than 21,000 signatures by noon on Friday.

Some football pundits and fans have criticised the design and price of the shirt since it was launched earlier this week.

An “authentic” version costs £124.99 for adults and £119.99 for children while a “stadium” version is £84.99 and £64.99 for children.

Sir Keir also called on Nike to reduce the price.

Despite the criticism, the FA has defended the design, saying that it was “not the first time” that different coloured St George’s Cross-inspired designs have appeared on England shirts.

“The new England 2024 home kit has a number of design elements which were meant as a tribute to the 1966 World Cup-winning team,” a spokesperson said.

“The coloured trim on the cuffs is inspired by the training gear worn by England’s 1966 heroes, and the same colours also feature on the design on the back of the collar. It is not the first time that different coloured St George’s Cross-inspired designs have been used on England shirts.

“We are very proud of the red and white St George’s cross – the England flag.

“We understand what it means to our fans, and how it unites and inspires, and it will be displayed prominently at Wembley tomorrow – as it always is – when England play Brazil.”