Four Chinese bus drivers facing possible jail for instigating Singapore's first industrial strike in 26 years were given more time on Wednesday to explore their legal options.

Liu Xiangying, 33, Gao Yue Qiang, 32, Wang Xianjie, 39, and He Jun Ling, 32, did not enter a plea when they appeared before a district court and were told to report again on December 19 for a new pre-trial conference.

"We need more time... in order for us to explore all options," said Mark Goh, a member of the legal team defending the drivers, who are yet to decide whether to plead guilty or not guilty.

"I need more time to take my client's instructions and to discuss with the DPP (Deputy Public Prosecutor)."

The drivers are currently out on bail posted by unnamed Singaporeans, a spokesperson for the legal team said.

Each driver faces a charge of engaging in a conspiracy to instigate a work stoppage from November 26-27 at state-linked transport firm SMRT, which was swiftly declared an illegal strike by the Singapore government.

He Jun Ling faces an additional charge of inciting his colleagues to go on strike through an online posting.

Staging an illegal strike is punishable by a maximum one-year jail term and Sg$2,000 ($1,640) fine. He's sentence could be stiffer because of the additional charge.

One driver has already been jailed for six weeks and another 29 deported for joining Singapore's first strike since 1968.

The strike by the non-unionised drivers highlighted the country's heavy dependence on migrant labour to drive its economic growth amid a labour shortage resulting from falling birth rates.

SMRT has promised to look into the strikers' demands, fumigate their bedbug-infested dormitory rooms and find them better housing but the government has vowed to take "firm action" against any future illegal strikes.