The lost ARA San Juan submarine has been missing for six days and there are fears the oxygen supply onboard the vessel is about to run out.

Several countries, including the US and Chile, have joined in the rescue effort, and Britain’s HMS Protector has been scouring the South Atlantic for the sub.

The Navy patrol ship is also being joined by HMS Clyde which has been diverted from South Georgia while the Royal Navy has deployed its elite submarine rescue team to help with the search.

But Argentina’s Workers’ Party leader Gabriel Solano tweeted: “F*** you! Pirates!”

Mr Solano: “You are responsible for war crimes, like the sinking of the General Belgrado.”

Earlier in the day the British embassy in Buenos Aires had tweeted that British forces were joining in the search, and Mr Solano responded by writing: “You are occupying troops in Argentine territories”.

Other Argentines blasted the politician as an “a**hole” for his comments.

Silvia Del Palacio said: “This must be a fake, this can’t be real, surely no-one can be this much of an A HOLE.” 

Noelia Lorenzo, using a union flag emoji, added: “You have no idea of human greatness, nothing at all. 

“You will never understand that those you love to hate, are giving everything to help Argentina. UK, such a gesture will never be forgotten."

Fernando Esteche, leader of the Quebracho party, also blasted the British deployment in the search.

On Twitter he wrote: “PIRATES NOW AND ALWAYS!!!!”

He too was criticised for spamming the British help, as the lives of the 44 crew members hang in the balance.

The Falkland Islands Twitter account replied to his comment writing: “The Royal Navy are out searching for missing Argentine sailors and this is what you tweet? What an a**hole.”