Senior Conservatives have asked England's chief prosecutor if the trial of two alleged Chinese spies could be resumed if the Government declares Beijing is a threat to national security.

The query, in a letter to director of public prosecutions (DPP) Stephen Parkinson, follows the collapse of the trial of Christopher Cash and Christopher Berry last month.

Both men, who deny wrongdoing, had been accused of passing secrets to China, but charges against them were dropped after the Government failed to provide evidence that would support the assertion that China represented a threat to national security.

Shadow home secretary Chris Philp and shadow Cabinet Office minister Alex Burghart wrote the letter asking Mr Parkinson to confirm "if the Government were to provide the evidence that the Crown Prosecution Service had requested, this would enable you to restart the prosecution".

The decision about whether to proceed with the prosecution was ultimately taken by the CPS, who were hamstrung by antiquated legislation that had not been updated by the previous Conservative government

Security minister Dan Jarvis

The letter comes as the Tories seek to keep up the pressure on ministers over the collapse of the case.

Ministers have denied that the Labour Government was responsible for the decision to drop the charges against Mr Cash and Mr Berry, and blamed the Conservatives' reluctance to designate China a threat while in office.

Security minister Dan Jarvis told the Commons on Monday: "The decision about whether to proceed with the prosecution was ultimately taken by the CPS, who were hamstrung by antiquated legislation that had not been updated by the previous Conservative government."

But Conservative leader Kemi Badenoch denied this was the case, arguing her party had described China as a "threat" on several occasions and suggesting the Government had decided that "closer economic ties with China were more important than due process and national security".

The 2021 Integrated Review described China as a threat to "economic security", while the 2023 refresh of that strategy stopped short of declaring Beijing a threat to national security.

Instead, the then-government described China as an "epoch-defining and systemic challenge", although it also committed to taking actions where the Chinese Communist Party posed "a threat to our people, prosperity and security".

Mrs Badenoch told Sky News in 2023 that the UK "should not be describing China as a foe".

Meanwhile, Labour deputy leadership contender Lucy Powell told the PA news agency she had been "disappointed" by the collapse of the case and MPs had wanted to see "tough action".

Labour deputy leadership contender Lucy Powell (PA)

She told PA: "People need to know there are consequences if they're trying to infiltrate our democratic processes in this regard, through all party parliamentary groups or working for an MP.

"These are absolutely sacrosanct, and people need to know that there are consequences if they're infiltrating our politics for nefarious means."

Questions have also surrounded the role of national security advisor Jonathan Powell in the collapse of the case, with reports alleging he and the Treasury had pushed for the charges to be withdrawn so as not to jeopardise the UK's economic relationship with China.

But Downing Street robustly denied suggestions that officials or ministers had taken any such approach.

The Prime Minister's official spokesman told reporters: "It is entirely false.

"There was no role for any member of this Government, no minister, or special adviser, to take any decision in relation to this case. That is entirely for the CPS."

And during a visit to Egypt for the signing of the Gaza peace deal, the Prime Minister himself told broadcasters he retained "full confidence" in Mr Powell.

Tories seek to keep up pressure over collapse of Chinese spying case