Jailed media tycoon Jimmy Lai Chee-ying has asked a Hong Kong court to overturn a decision by the government that a British king’s counsel should not represent him at his collusion trial as it would likely undermine national security.

Tuesday’s High Court filing revealed the city’s Committee for Safeguarding National Security had earlier concluded that allowing Timothy Owen to defend Lai would likely constitute a risk “contrary to the interests of national security”.

Director of Immigration Au Ka-wang, one of the committee’s members, said in an affidavit the body decided on January 11 it would advise the Immigration Department to refuse any application by Owen for an extension to his working visa if he sought to join Lai’s legal team.