Britain is to support a ban on international trade in blue-fin tuna after a high-profile campaign by film stars such as Greta Scacchi, Sienna Miller and Charlize Theron.

Huw Irranca-Davies, the Fisheries Minister, who met Ms Scacchi recently, said that Britain was joining France and Monaco in calling for the fish to be listed on the Convention for International Trade in Endangered Species (Cites).

The World Wildlife Fund has predicted that blue-fin tuna breeding stock could disappear by 2012. It said that analysis of official data showed that the average size of mature blue-fin tuna had more than halved since the 1990s.

The fish is a favourite of sushi-lovers and is on the menu at the two London branches of Nobu, the restaurant chain part-owned by the actor Robert De Niro.

A spokeswoman for Nobu last night said that it would continue to serve blue fin-tuna despite the Government’s announcement.

“We are keeping it on the menu. It is not illegal on this date. We allow our guests to make up their own minds.”

Last year, Nobu’s London restaurants added a note to the menu advising customers that the species was “environmentally threatened” and suggesting that they ask the waiter for an alternative. This note is not on the menus in the other 24 Nobu restaurants around the world.

Last month a group of celebrities, including the comedian Stephen Fry, the singer Sting, the model Elle Macpherson, as well as Miller and Theron, wrote a joint letter to Nobu calling on it to stop selling the fish.

They wrote: “We feel strongly that blue-fin tuna must be completely removed from your menu as it is an extremely endangered animal.”

Mr Fry said: “It’s lunacy. There’s no justification for peddling extinction.”

A spokeswoman for the Department for Environment, Food and Rural Affairs said that Britain would support the addition of blue-fin tuna to the species listed in appendix one of Cites. Trade in these species is prohibited and they can only be caught for scientific research.

The 175 countries that have signed the convention will vote on the proposed ban at a meeting in Doha, Qatar, in March next year. A two-thirds majority is required and, if this is achieved, the ban would come into force 90 days later.

Mr Irranca-Davies said: “The UK supports calls from Monaco and France to list blue-fin tuna on the Cites. This follows growing public concern about the perilous state of blue-fin tuna stock. We encourage other Member States to support this proposal and we will be working through the EU to build support for Cites listing. Action being taken at EU level to encourage more responsible fishing is essential to improve the state of the stock.”

The hardening of Britain’s position came a few hours after President Sarkozy announced that France was supporting a ban.

President Sarkozy said: “Ours is the last generation with the ability to take action before it’s too late — we must protect marine resources now, in order to fish better in future. We owe this to fishermen, and we owe it to future generations.”

Dr Sergi Tudela, head of fisheries at WWF Mediterranean, said: “This iconic species is simply at the end of its tether. WWF hopes to see a sustainably managed and thriving fishery in future, but to enable this recovery the species must be given a breather — if the world does not put the brakes on its voracious appetite now, an amazing species and fishery could be lost forever.”