Argentina’s Malvinas secretary has warned that unilateral British drilling for oil and gas in the Falklands could unleash an environmental catastrophe on the scale of the Gulf of Mexico disaster.

Speaking in London, Daniel Filmus, the first holder of the post which was created in January, said attempts by British companies to extract hydrocarbons from the seabed without Argentina’s consent were hugely dangerous.

Several small UK firms are exploring the waters around the islands, believed to contain billions of dollars worth of oil and gas revenues. Filmus warned that without “continental support” from Argentina these technically difficult projects risked a major oil spillage across the pristine South Atlantic.

Buenos Aires has banned ships carrying the British flag from visiting its ports or carrying out “logistical operations”. Other South American nations including Brazil, Paraguay and Uruguay have followed suit.

“The environmental risk of exploring for oil in the region is huge. Not just for the islanders, but for the whole of Latin America and even the world. It means potentially undermining biodiversity,” Filmus said. “You can’t explore without proper support from the continent. The risk of another accident like the Gulf of Mexico is huge.” Argentina’s government was suing the companies involved for their “criminal actions”, he said.

Filmus added he would continue to press Britain to return the islands using peaceful means and dialogue. He said Argentina would respect the right of the islanders to remain British but wanted “the exercise of sovereignty”.

“The history of humanity is the history of the end of colonialism,” he said. “I’m certain those living on the islands will have a better life [with Argentina].”

Filmus is a close ally of president Cristina Fernández de Kirchner, who has rekindled Argentina’s claim to the Falklands (known in Argentina as the Malvinas). Filmus said he did not attempt to meet anyone from the British government during his one-day trip to London on Monday, following an earlier snub from former foreign secretary William Hague. The envoy launched a book, Dialogue, – which sets out Argentina’s argument in a series of essays and articles.

Argentina has said it will sabotage what it regards as illegal oil exploration around the islands. Last year parliament voted to impose jail sentences of up to 15 years on executives whose companies drill for oil, as well as punitive fines of up to $1.5bn. It has said firms will also be disbarred from lucrative work in Vaca Muerta, a giant shale oil deposit in Argentina’s Patagonia region.

Oil majors such as Chevron and BP have so far avoided the dispute. But smaller, UK-based firms such as Premier Oil are exploring the seabed, including the North Falklands Basin, believed to contain 400m barrels of recoverable oil.

Filmus said Argentina’s claim to the Malvinas went back to 1833, when Britain illegally seized the territory. International law, other South American nations, and binding UN resolutions all obliged Britain to negotiate over the future of the islands, he said. “We regret that the UK stopped dialogue. The only way of resolving a conflict is through talks.” Britain secretly negotiated over the islands’ future between 1966 and 1982 with successive Argentinian dictatorships, but now refuses to discuss the issue with a democratic and war-eschewing Argentina, he said.

The envoy, meanwhile, said Buenos Aires had no intention of banning the BBC Top Gear presenter Jeremy Clarkson, who drove around Argentina in a Porsche with the registration H982 FLK, an apparent reference to the 1982 Falklands War. Last week Argentina’s ambassador to the UK, Alicia Castro, made a formal complaint to the BBC.

“I don’t think we want to dedicate one second to Clarkson,” Filmus said.