BRITAIN must prepare for war on home soil for the first time in decades, ministers warned today.

An alarming new national security outline indicates that the UK might encounter a “wartime scenario” for the first time “in many years,” as threats from adversaries like Russia, China, and Iran intensify.

This grave warning coincided with the Prime Minister’s arrival in The Hague for a crucial NATO summit, where leaders confirmed intentions for all member nations to allocate 5 per cent of GDP toward defence and security by 2035.

Sir Keir Starmer acknowledged that the nation faces “daily challenges on the home front” when questioned about the increasing threat following the release of the security strategy.

He pointed to “very, very frequent” cyber attacks and warned energy supplies were being used as a weapon by Britain’s enemies.

The PM added: “In the United Kingdom, we have to guard properly against those threats and we will do so.”

The Government’s strategy lays bare the scale of the danger, warning: “We are in an era in which we face confrontation with those who are threatening our security.

“For the first time in many years, we have to actively prepare for the possibility of the UK homeland coming under direct threat, potentially in a wartime scenario.”

The new plan focuses on three key areas – protecting the UK at home, working with allies to strengthen global security, and rebuilding Britain’s defence industries and technological capabilities.

But the PM is now facing growing pressure to explain how they will afford the huge jump in defence spending needed to meet NATO’s 2035 target.

The 5 per cent pledge includes 3.5 per cent for core defence spending and 1.5 per cent on wider security like energy, cyber defences and border protection.

Experts say hitting 3.5 per cent alone could cost taxpayers an extra £40 billion a year – but the PM has refused to say how it will be paid for.

Pressed on whether taxes will rise to meet the bill, he said: “Every time we’ve set out our defence spending commitments, so when we went to 2.5% in 2027/28, we set out precisely how we would pay for it, that didn’t involve tax rises.

“Clearly we’ve got commitments in our manifesto about not making tax rises on working people and we will stick to our manifesto commitments.”

But the manifesto only applies for this Parliament – leaving the door wide open to tax hikes after the next election, when the most expensive part of the NATO pledge kicks in.

Institute for Fiscal Studies director Paul Johnson warned that the defence spending increase would need to be funded by “£30 or £40bn more taxes”.

Speaking to Times Radio about the increase, he said: “Where that’s going to come from, goodness only knows.

“Well, I think we do know it’s going to come from; £30 or £40bn more taxes, because in the end there’s nowhere else it can come from.

“I can’t really see this government cutting spending on pensions or the health service or welfare or what have you by that amount. I mean they can’t.”