In a letter sent to MPs, House of Commons Speaker Sir Lindsay Hoyle, warned that the woman, named as Christine Lee, had "engaged in political interference activities on behalf of the Chinese Communist Party, engaging with members here at Parliament".
He said he had been alerted by security bosses claiming she had reached out to MPs, hopeful MPs and members of the now-defunct all-party parliamentary group, Chinese in Britain.
Issuing the Security Service Interference Alert, MI5 said Ms Lee had “acted covertly” in co-ordination with the United Front Work Department of the Chinese Communist Party, and is “judged to be involved in political interference activities in the UK”.
The security agency noted that it believes the arm of the Communist party “is seeking to covertly interfere in UK politics through establishing links with established and aspiring parliamentarians across the political spectrum.”
It said the department of the ruling Chinese party “seeks to cultivate relationships with influential figures in order to ensure the UK political landscape is favourable to the CCP’s agenda and to challenge those that raise concerns about CCP activity, such as human rights.”
“Lee has been engaged in the facilitation of financial donations to political parties, parliamentarians, aspiring parliamentarians and individuals seeking political office in the UK, including facilitating donations to political entities on behalf of foreign nationals,” it added.
“Lee has publicly stated that her activities are to represent the UK Chinese community and increase diversity. However the aforementioned activity has been undertaken in covert co-ordination with the UFWD, with funding provided by foreign nationals located in China and Hong Kong.
“Lee has extensive engagement with individuals across the UK political spectrum. including through the now disbanded All-Party Parliamentary Chinese in Britain Group, and may aspire to establish further APPGs to further the CCP’s agenda.”
The alert warned that anyone contacted by her should be “mindful of her affiliation with the Chinese state and remit to advance the CCP’s agenda in UK politics”.
Sir Lindsay reminded MPs that they are responsible for verifying the source of donations and recording all money that is handed over.
The letter urged MPs to report any approaches or concerns and said the Lord Speaker, who oversees proceedings in the House of Lords, had also written to peers to warn them.
The warning came to light after Sir Iain Duncan Smith, a Conservative MP and former party leader, raised a point of order in the Commons. He is under sanctions by the Chinese government for speaking out against the state’s persecution of Uighur Muslims.
“I understand that Mr Speaker has been contacted by MI5 and is now warning members of Parliament that there has been an agent of the Chinese government active here in Parliament working with a Member of Parliament, obviously to subvert the processes here,” Sir Iain told the House.
Labour MP Barry Gardiner was named as a politician who received donations from Ms Lee.
The suspect’s son had worked as a diary manager for the opposition MP but resigned on Thursday, hours before the discussion in Parliament.
Mr Gardiner said his office had been liaising with MI5 for many years over concerns about Ms Lee. He said the final donation from her was received in June 2020.
“They have always known, and been made fully aware by me, of her engagement with my office and the donations she made to fund researchers in my office in the past,” he said.
“Steps were taken to ensure Christine Lee had no role in either the appointment or management of those researchers. They are also aware that I have not benefited personally from those donations in any way.”
He said all the donations were properly reported and “their source verified at the time”.
Mr Gardiner said he had been given assurances from security services that while they have found evidence that Ms Lee had facilitated donations of improper funding, none of these went to his office.