Britain has called on FIFA to sanction Argentina after its players celebrated knocking England out of the World Cup with a banner asserting Buenos Aires’ claim to the Falkland Islands.

The defending champions beat England 2-1 in Wednesday’s semifinal to set up a final against Spain. After the final whistle, Lisandro Martinez and Giovani Lo Celso briefly held up a banner reading “Las Malvinas son Argentinas” (“The Falkland Islands are Argentinian”).

The South Atlantic archipelago, located about 300 miles east of Argentina, has remained a point of contention between London and Buenos Aires since the 74-day Falklands War in 1982, which ended in Argentina’s defeat. Argentina says it inherited the islands after gaining independence from Spain in 1816, while Britain considers them a British Overseas Territory.

The display prompted an angry response from British politicians. Business Secretary Peter Kyle urged FIFA to launch “a proper inquiry,” calling the banner “entirely inappropriate” and an “egregious violation” of the governing body’s rules. Liberal Democrat leader Ed Davey said the players who displayed it should be barred from Sunday’s World Cup final.

Downing Street later backed calls for an investigation. Prime Minister Keir Starmer’s spokesman said: “The World Cup might not be ours, but the Falkland Islands definitely are.” While stressing that any disciplinary action is “a matter for FIFA,” he said that Starmer agreed the incident should be investigated.

FIFA and the International Football Association Board (IFAB) do not allow political, religious, or personal messages during matches. Penalties range from fines and suspensions to points deductions and bans.

The football governing body has not commented on the incident. Argentina was fined in 2014 after displaying the same “Las Malvinas son Argentinas” banner following a friendly against Slovenia.

The incident is the latest political flashpoint at this year’s tournament. Last month, spectators at Iran’s match in Los Angeles displayed Iran’s pre-1979 national flag, a symbol used by opponents of the government in Tehran despite FIFA’s ban on political messaging.

The tournament has also been marred by controversy over visas, ticket prices, and refereeing, including FIFA lifting US striker Folarin Balogun’s suspension after reported lobbying by President Donald Trump, Washington denying entry to Somali referee Omar Abdulkadir Artan despite his having a valid visa, and Iran being forced to base its team in Mexico after initially being barred from training in the US.