Rishi Sunak has been accused of having no clear strategy on China, leaving the UK's future security "handicapped".
Sir Keir Starmer said the PM failed to heed warnings and was "desperately playing catch up", during the weekly Prime Minister's Questions session.
The Labour leader repeated his call for a "full audit of UK-China relations".
Mr Sunak said the UK had the "most robust policy" on China it had ever had and was in line with the country's international allies.
It comes amid ongoing controversy about the arrest, in March, of a parliamentary researcher on suspicion of working as a Chinese agent.
The man, who was one of two arrested under the Official Secrets Act, has issued a statement through lawyers saying he is "completely innocent".
Sir Keir said it was a "serious security concern", adding that some MPs face sanctions, intimidation and threats from the Chinese state.
He asked the prime minister if Foreign Secretary James Cleverly had raised concerns about the alleged spy when he held talks with his Chinese counterpart in Beijing last month.
Mr Sunak said: "The Foreign Secretary raised these issues with the Chinese foreign minister who he met, as did I when I had my meeting with premier Li (Qiang) over the weekend."
Sir Keir replied: "Well, that certainly wasn't a yes."
The Labour leader said Mr Sunak's claims that the UK had a robust policy on China were at odds with a report by Parliament's intelligence and security committee July this year.
"That (report) set out that the government has no clear strategy when it comes to China," said Sir Keir.
"This has been raised time and time again. But, yet again, the prime minister fails to heed the warnings and he's now desperately playing catch up.
"So, will he finally commit to the full audit of UK-China relations which so many in this House have so long demanded?"
Mr Sunak said it was Sir Keir who was "playing catch up" because the committee's report relates to 2019 and 2020.
"Since then the UK has launched a new integrated review refresh of the China strategy and has put in place "a range of new measures, including... the National Security Protective Agency", he added.
On Monday, Deputy Prime Minister Oliver Dowden told MPs the foreign secretary "regularly" raises interference in the UK's democratic institutions "with his Chinese opposite number".
But he added: "Specific cases, particularly those that are subject to an ongoing police investigation, would not, as is generally the case, be raised."
Senior Tory MPs - including former PM Liz Truss - stepped up calls for China to be officially designated as a "threat" to the UK.
Mr Dowden said the government was "clear about the threat that China represents" but it was also "right that we engage with China", while "working very closely with our allies".
In a separate development, The Times reported that the Conservative Party had been warned by MI5 that two possible parliamentary candidates could be spies for Beijing.
The story has not been denied by the Conservatives, with a spokesman saying that "when we receive credible information regarding security concerns over potential candidates we act upon them".
The newspaper did not publish any details of the potential candidates in question, or how far through the candidate selection process they progressed.
A senior source told the BBC's chief political correspondent Henry Zeffman that that security services had occasionally warned the Conservative Party to "be careful" about individuals attempting to get on in politics.
But they said these warnings were rare, as well as typically being vague about the reasons for suspicion about the people concerned. The security services do not systematically "vet" Conservative candidates - instead any contact is proactive on their part.
Separately, the BBC has been told that senior government officials have been warned not to discuss sensitive work in pubs around Parliament for fear that agents of hostile states are eavesdropping.