Britons should prepare for food shortages if “state-sponsored terrorism” disrupts everyday life, the defence secretary has said in a stark new warning on the “real” threats facing the UK.

People need to start to stockpile food, water, medicine and wind-up radios, Wes Streeting said, raising the spectre of hostile powers launching cyber attacks on key infrastructure.

Such attacks could wreck supply chains or make businesses’ payment systems fail, he said, while natural risks such as flooding and wildfires also pose a threat.

Speaking at the official opening of Gun Hall, a new tank gun barrel factory, in Telford, Shropshire, Mr Streeting said people should ask themselves whether they were prepared for the consequences of “increasingly sophisticated cyberattacks on our businesses”.

He said: “Are they prepared for the eventuality that there may be disruption to essential supply chains caused by hostile state actors or terrorists?” he asked. “How would we cope if the payment systems of the supermarkets went down?

“Those are the sorts of everyday challenges and threats we could well face, and it is right we ask the country to be ready for those things and ask everybody to do their bit.”

The fresh warning comes just weeks after the government told householders to keep bottled water and non-perishable food at home under a new national resilience campaign designed to prepare households for possible disruption.

Now, the government has issued a “Be ready” checklist, which includes advice on stocking up on such items, as well as a first-aid kit, hand sanitiser and pet food.

It comes hours after a large-scale cyber-security issue affecting millions of sites worldwide forced websites worldwide and dozens of government services to go offline on Wednesday. Authorities and companies globally have been racing to update their systems to prevent catastrophic attacks by hackers after vulnerabilities were exposed by artificial intelligence giant OpenAI.

But as companies and governments deployed patches and suspended websites as ‌a precaution, hacking attempts surged into the millions, according to Cloudflare.

The latest government warning on state-sponsored threats comes amid rising fears over the risk of conflict with Russia, which has become increasingly hostile towards the UK.

In the summer, the Kremlin warned there would be “consequences” for Britain providing Ukraine with blueprints for British components used in French-produced Scalp missiles.

Russian foreign minister Sergei Lavrov said his country had a right to regard the “direct involvement of British missile forces” as “participation in the war, with all the ensuing consequences”.

Lord Peach, the former chief of the defence staff, has warned that Britain is not prepared to deal with potential threats to the nation, such as widespread power cuts and full-scale war.

“The fact that Russia intends us harm – whether it’s economic disruption or the ‘dark arts’, as you might call them – I think the evidence is clear,” he told .

Malicious attacks can cause “real damage”, he said, pointing to a politically motivated arson attack in Berlin that left 45,000 households and 2,200 businesses without electricity or heating.

And Lord Robertson, the ex-Labour defence secretary who wrote the government’s Strategic Defence Review, warned this year that Britain was “under-prepared and under-insured”. “We are under attack. We are not safe... Britain’s national security and safety is in peril,” he said.

At the official opening of Gun Hall, Mr Streeting announced that the UK would be producing weapon parts for tanks for the first time in two decades.

A German arms company will be manufacturing the parts to ramp up the UK’s supply chain as the government prepares for a potential war with Russia.

The factory will create 100 jobs there and hundreds more across the supply chain, the defence secretary announced.

Pressure has been mounting on Labour to increase defence spending to 3 per cent of GDP in the face of intensifying global threats.

The head of the army last week predicted the UK’s political leaders would soon be having a “frank conversation” with the public about the sacrifices needed in the event of war.

General Sir Roly Walker, the chief of the general staff, has said citizens must “consent to sacrifices to prioritise defence and security”.

As well as a minimum of three litres of drinking water per person per day and tinned or other non-perishable food, the checklist of items to keep ready also includes torch, batteries, blankets, sleeping bags, warm clothing, cash, identity documents, important phone numbers, vital medication, baby formula and nappies.

The checklist advises people to build up supplies gradually, picking up one or two extra items when possible.

Keeping cash is advised in case banks are hit, making card payments impossible.

Mr Streeting went on: “Terms like hybrid warfare and grey zone threats do not accurately capture or convey to the general public what I prefer to describe as state-sponsored terrorism.

“So in the face of those threats, which are not hypothetical but real, and not somewhere else but increasingly here, we have to step up and take seriously our national resilience as well as our national defence.”

Gun Hall will also “support the next generation of equipment for the British Army, helping to deliver the firepower that will make us warfighting ready by 2030”.