The four alleged ringleaders of November's illegal bus strike look set to go to trial after they refused to plead guilty on Friday.

In doing so, the Chinese Nationals rebuffed the prosecution's offer to amend their charges in January. If they had accepted the offer, the four men, Gao Yue Qiang, 32, Liu Xiangying, 33, Wang Xianjie, 39, and He Jun Ling, 32, would have been charged for taking part in the Nov 26 illegal strike, rather than instigating it.

Their lawyers will meet prosecutors in chambers on Feb 8 to set the trial dates. He's lawyer Choo Zheng Xi told reporters after Friday's pre-trial conference that he had requested to meet on a later date but was turned down by the judge.

He disclosed that he was in the midst of translating some 200 Chinese messages that were posted by some 100 SMRT bus drivers, including He, on Chinese social networking portal QQ to get more information for his client's case.

"It is just not possible to complete the process by Feb 8," said Mr Choo.

Separately, Gao discharged his lawyer Tan Wen Hsien and is said to be looking for another lawyer to represent him.