The US remains our most critical ally, but partnerships require commitment.

As the Prime Minister prepares to meet President Trump this week, he cannot arrive in Washington empty-handed.

It is no longer an option to make vague announcements; there must be clarity to both the military and the British people.

As a bare minimum he must present a clear, credible roadmap for increasing defence spending to 2.5% of GDP by 2030.

The reason this must be the bare minimum is because, as I said in the Sunday Express, I now believe we will need to go further and faster than the previous commitment to 2.5% we set out last year.

But making the defence budget our top priority will mean making bold decisions on public spending elsewhere – and we stand ready to support the government in making those tough choices.

If safeguarding our future means reallocating resources, we must have the courage to do so.

That includes targeted reductions in welfare and, at least in the short term, foreign aid, to ensure our military has the funding it needs to defend Britain and its allies.

Without clear and long-term commitments, Britain’s security is under threat.

The last Conservative government understood this and took real action, committing to increase defence spending to 2.5% of GDP by 2030.

This is no longer a debate; it is a necessity. The security of Britain and Europe is at stake and it is clear the US is increasingly going to concentrate on the threat from China, needing us to do more to stand up to the Russian threat.

Prior to stepping into the White House on Thursday, Starmer must have something concrete to offer and set a firm timeline for when he will increase defence spending. Anything less would be a failure of leadership.

James Cartlidge is the shadow defence secretary