An assistant director of environmental protection, Kenneth Leung, said on Wednesday that the government plans to test hydrogen buses on two routes by the end of next year.

He said the administration hopes to compare the performance and operational differences of buses powered by hydrogen, electricity and diesel during a one-year-trial.

The official told an RTHK programme that after collecting the data, the government will devise a plan in the hope that all vehicles will be emission-free before 2050.

Leung also welcomed recommendations put forward by a consortium of bus operators, power companies and green groups, saying a timetable for all commercial vehicles to be environmentally friendly will be released in around 2025.

"If we are to achieve zero emissions by 2050, the last diesel-run commercial [vehicles] would be sold before 2032. Of course, we hope it could be done sooner. If the testing of new energy vehicles, especially heavy vehicles, goes smoothly in the next few years, then we will be able to come up with a more aggressive timetable," he said.

On the same programme, a member of the consortium, Lawrence lu from Civic Exchange, said he hopes the government will conduct the testing of hydrogen buses as soon as possible and build the supporting infrastructure to facilitate the trial.