HONG KONG - The nine leaders of the Umbrella Movement of massive rallies that brought Hong Kong to a standstill for 79 days in 2014 will be sentenced on April 24.

It comes after a court in West Kowloon on Wednesday morning (April 10) heard mitigation pleas from some of the leaders, as well as submissions from the prosecution.

Senior Counsel Wong Ching Yu urged the court to hand Civic Party legislator Tanya Chan a community service order or suspended prison sentence.

The Basic Law states that lawmakers will lose their seats if they go to jail for more than one month for a criminal offence and a motion to relieve them of their duties is passed by two-thirds of Legislative Council members present.

There are 70 seats on the council and pan-democrats hold 26 seats.

Senior Counsel Hectar Pun, acting for former student leader Tommy Cheung, said a custodial sentence should be a last resort, as his client was only 20 years old at the time of the offence.

The mitigation pleas follow the conviction of all nine on Tuesday.

The three prominent leaders of the group - sociology professor Chan Kin Man, 60, law professor Benny Tai, 54, and Baptist minister Chu Yiu Ming, 75 - were each convicted of conspiracy to cause public nuisance. Chan and Tai were also found guilty of inciting others to cause public nuisance.

All three were acquitted on a third charge of incitement to incite public nuisance.

Lawyers for the three submitted mitigation pleas to the court on Wednesday. Chan and Tai had urged the court to spare Chu from a prison sentence, as the latter suffers from medical conditions.

Each charge carries a prison term of up to seven years.

District Court Judge Johnny Chan wrote in a 268-page judgment that while Hong Kong courts recognised the notion of civil disobedience, it "is not a defence to a criminal charge".

"It is naive to suggest that a concession to introduce the form of universal suffrage advocated by the trio could be made by the government overnight with a click of fingers," he wrote.

Five of the remaining six leaders - lawmakers Chan and Shiu Ka Chun, former student leaders Cheung and Eason Chung, as well as activist Raphael Wong - were each convicted of two charges: inciting others to cause public nuisance and inciting people to incite others to cause public nuisance. Former legislator Lee Wing Tat was convicted of one count of inciting others to cause public nuisance.

Hong Kong's last governor Chris Patten said on Tuesday that the trial was the result of a "vengeful" campaign by the city's authorities, while China's Foreign Ministry threw its weight behind the Hong Kong government in "punishing" the movement's organisers.

Ministry spokesman Lu Kang said in Beijing on Tuesday: "I also want to remind people in other countries that it is unreasonable to see this as damaging the freedom of Hong Kong society. Just look at what happened in other countries and you can draw a fair conclusion."

The charges laid against the nine were brought about by the Department of Justice more than two years after the protests ended, a move that drew criticism from human rights and pro-democracy groups.

Since the protests, several activists have been prosecuted, with some jailed. Some pro-democracy lawmakers have also been banned from contesting elections.