Current plans and preparation in the event of nuclear war have been revealed by the council, amid escalating tensions with Russia.

Defence ministers and military analysts have warned in recent days of the need to prepare for a conflict with Russia in the coming years as the war in Ukraine continues for a third year.

Boris Pistorius, German defence minister, suggested that Russia could attack the NATO alliance win “five to eight years” in an interview with Der Tagesspiegel.

Although he said such a conflict was unlikely “for now”, he highlighted threats made by the Kremlin towards Baltic countries, who are members of NATO, with nations such as the United States and the United Kingdom duty-bound to defend them if attacked.

In a Freedom of Information request, Brighton and Hove City Council revealed that, in the event of a nuclear exchange, a meeting of the government's COBRA committee would be convened, with authority led by central government directive.

Locally, the Sussex Resilience Forum (SRF) has contingency measures in Sussex in the event of the release of chemical, biological, radiological or nuclear contamination.

The council said: “Roles and responsibilities for blue light services (police, fire service, ambulance), local authority (provision of shelter) and the Environment Agency (disposal of contaminated material) are set out in this plan.

“The SRF Sussex Response and Recovery Plan would be triggered as well as the SRF Warning and Informing Plan which sets out expectations for communicating with the public during an emergency.

“Dependent on the size and scale of the incident, the SRF Mass Casualties and Mass Fatality Plan could also be triggered.”

On a city level, the council said the Brighton and Hove Major Incident Plan would likely be triggered, with “rest centres” created to care for “displaced residents” in the short term, with food provided for those left homeless by the attack.

For those unable to return home, the council’s Housing Options team would provide “accommodation solutions”.

The council’s emergency planning team have agreements with local supermarkets to provide food in the event of an emergency and restaurants, community groups and voluntary services could be called upon to provide support.

“It is difficult to assess how food supply chains would be affected by an attack,” the council said.

Speaking to Sky News about the prospect of a Third World War with Russia, Dr David Wearing, University of Sussex lecturer for international relations, said that the current international situation is more perilous than in 1914 and 1939 due to nuclear weapons.

He said: “The danger here is not that one side takes the pre-meditated decision to spark the apocalypse, but rather that a conflict or area of tension escalates to a certain point, one party makes a move that another party misinterprets, and then a nuclear exchange begins despite the fact that no-one was looking for one.

“We should take that risk very seriously, especially over Ukraine and Taiwan.”