A political row over former media boss Jimmy Lai Chee-ying has intensified after his guilty verdict, with the Hong Kong government condemning what it called “despicable political manipulations” and the United States calling for his release.

Beijing’s top office overseeing city affairs also published a strongly worded commentary on Tuesday, criticising Lai for using “two systems” to oppose “one country” and branding him a “national criminal who will forever be nailed to the pillar of historical shame”.

The clash followed Monday’s guilty verdict against the 78-year-old founder of the now-defunct Apple Daily newspaper.

Lai was convicted of two conspiracy counts of collusion with foreign forces and a third of conspiracy to print and distribute seditious articles in his national security trial.

US President Donald Trump told reporters that he had urged leniency for Lai during a call with his Chinese counterpart, Xi Jinping.

“I feel so badly. I spoke to President Xi about it, and I asked to consider his release,” Trump told reporters, without specifying exactly when the conversation took place.