The Conservative Party took “swift action” to drop two potential candidates to become MPs after MI5 warned they could be Chinese spies, a Government minister said.

The security service advised the Tories in 2021 and 2022 that the two hopefuls should not be included on the central list of candidates, The Times reported.

It comes as ministers continue to face questions about allegations of espionage in Westminster after the arrest of a parliamentary researcher on suspicion of spying for Beijing.

Health minister Maria Caulfield said her party had responded quickly after being given the warning about the would-be MPs.

“I think, whichever party is in government, there will always be those who are trying to target it, either to get information or to influence,” she told Times Radio.

“The story that we have heard about today, about the candidates who the Conservative Party were warned about, swift action was taken and they were removed from the list. They are not standing for election.

“Any intelligence that comes forward, it just shows that we will take that very seriously; the same with the researcher in Parliament.

“It does show that there are other nations always wanting to infiltrate government of all parties. But we have shown that we take that seriously and act swiftly when that intelligence comes forward.”

MI5 is said to have raised concerns that the pair had links to China’s United Front Work Department, a body charged with influencing global opinion.

The Times cited an unnamed source as saying it was made “very clear” to the Conservatives that the candidates “posed a risk”.

“They were subsequently blocked from the candidates list. They weren’t told why.”

A Conservative Party spokesman said: “When we receive credible information regarding security concerns over potential candidates we act upon them.”

Rishi Sunak
Rishi Sunak has been under pressure to act amid a row over alleged Chinese spying at Westminster (Dan Kitwood/PA)

The claims will fuel debates about the UK’s relationship with China following the arrest of the 28-year-old parliamentary researcher – who maintains he is completely innocent – under the Official Secrets Act.

The Briton was arrested, along with another man in his 30s, by officers on March 13 on suspicion of spying for Beijing, it was revealed by the Sunday Times.

Officers from the Metropolitan Police’s Counter Terrorism Command, which oversees espionage-related offences, are investigating.

Both were held on suspicion of offences under Section 1 of the Official Secrets Act 1911, which punishes offences that are said to be “prejudicial to the safety or interests of the state”.

They have been bailed until early October.

The arrests were only revealed at the weekend and the researcher at the centre of the row had links with senior Tories including security minister Tom Tugendhat and Foreign Affairs Committee chairwoman Alicia Kearns.

The allegations have led to increased pressure from China “hawks” on the Tory benches for Prime Minister Rishi Sunak to toughen his stance towards Beijing.