Sir Keir will be hoping his visit – the first by a UK prime minister since Theresa May in 2018 – will mend relations with China, while keeping US President Donald Trump on side.

He has insisted the UK will not be forced to “choose between” China and the US, amid rising trade tensions between the two superpowers in recent years.

The UK would maintain “close ties” with the US on business, security and defence, he said, but added that “sticking your head in the sand and ignoring China… wouldn’t be sensible”.

The PM’s visit has attracted fierce criticism from his political opponents in the UK, particularly after the government gave the go-ahead to controversial plans for a Chinese mega-embassy in London.

Conservative leader Kemi Badenoch said she would not visit China “at this time” if she was prime minister.

“We should be talking more to those countries who are aligned with our interests, not the country that is doing everything it can to undermine our economy,” she told reporters.

“I think that that is what the prime minister should be talking about and he needs to show strength, not approving a super-embassy which many people think is going to become a spy hub.”

She had earlier said she was “worried about what he’s [Starmer] going to be doing when he gets to China”.

“He’s probably going to give away the Isle of Wight before he comes back. Let’s have an actual foreign policy, one that is rooted in realism and focusing on Britain’s national interest,” she added.

Sir Keir also faced criticism from the Liberal Democrats in the House of Commons, where deputy prime minister David Lammy stood in for him at his weekly question time session.

Lib Dem deputy leader Daisy Cooper said: “Whilst the Chinese regime still holds British citizen Jimmy Lai captive in prison, and whilst the Chinese regime continues to hunt down pro-democracy protesters on the streets of Britain with bounties on their heads, the British prime minister has gone cap in hand to China to ask for a trade deal on the promise of a super-embassy from which the Chinese regime will continue to spy on us.”