Mr Lai, the publisher of Apple Daily, who was unharmed in the attack, is a vocal supporter of the democracy movement that has brought protesters on to the streets for 13 consecutive weeks.

He has been labelled a traitor by state media in mainland China.

Even as the Hong Kong government tried to turn down the temperature in the territory’s political crisis, the attack demonstrated the strength of opposition in some quarters towards supporters of the movement.

The sharp divide in public opinion has also seen action taken against companies and individuals seen as opponents of the protests. On Thursday morning, the MTR Corporation, the company that operates the city’s transit network, said one of its employees was taken to hospital after being attacked by anti-government protesters.

A spokesman for Mr Lai, Mark Simon, accused organised crime gangs known as triads of being involved in the attack. Mr Simon, often referred to as Mr Lai’s right-hand man, adding that “no more fire bombs” should be thrown by anyone.

“That firebomb tossed at Jimmy’s house was as effective as the ones thrown at the cops during the protests, which means not at all,” Mr Simon said.

The attack on Mr Lai follows attempts by Carrie Lam, Hong Kong’s chief executive, to find a solution and to mollify protesters this week by withdrawing a controversial bill that would have allowed extradition of criminal suspects in Hong Kong to China for the first time.