That was despite Cheung's public apology yesterday for his poor handling of the construction delay and not telling legislators about it.

"I should have told lawmakers … back" on November 22, Cheung said at a meeting of the Legco railways subcommittee. "I apologise to Legco and members of the public. I am willing to bear the criticism."

Asked repeatedly by lawmakers to quit, he said: "I feel remorseful for the incident. After years in politics, I understand that politicians have to face various challenges and choices. I have been reflecting."

Cheung said he had wanted to tell lawmakers at a November 22 meeting that the rail link might not be ready by the target of 2015.

But he changed his mind after MTR Corp chief executive Jay Walder called him the day before to assure him that the existing schedule was still feasible.

On Saturday, Cheung said he had given the MTR Corp "the benefit of the doubt".

Civic Party lawmaker Claudia Mo Man-ching said Cheung's "integrity was in doubt". "My impression is the government has shed its responsibility and blamed it all on the MTR Corp for bad management," Mo said.

"Some lawmakers have proposed a vote of no confidence against you, which I tend to support, so my question is, minister, would you consider stepping down?"

League of Social Democrats chairman "Long Hair" Leung Kwok-hung echoed the question.

Others wondered aloud if a new investigation was in order.

Helena Wong Pik-wan, a member of the Democratic Party (of which Cheung was vice-chairman in the early 1990s), said lawmakers should exercise their authority under Legco's powers and privileges ordinance to establish an investigative committee.

Did the government and MTR use "one lie to cover up another?" she asked.

Executive councillor Regina Ip Lau Suk-yee said Cheung had clearly committed a "grave error in judgment", but invoking Legco's special powers might be a waste of public funds.

"I don't see what purpose a P&P can serve at this stage … other than to get more heads rolling," she said.

Timetable for the Guangzhou trains that are running late

Construction starts on the fully underground, 26-kilometre Hong Kong section of the high-speed railway to Guangzhou.

MTR projects programme team realises work on northern part of West Kowloon terminus and tunnel linking Mai Po and Shenzhen's Huanggang Park is significantly behind schedule. MTR decides rail project is still on track for completion in 2015.

Contractors estimate terminus will be finished only in June 2016. MTR urges them to look for solutions to catch up with schedule.

MTR realises 2015 target can be met only if it opens terminus in stages, putting only six of 15 tracks into use initially.

MTR executive committee agrees with partial opening.

Highways Department is briefed on partial opening. It does not indicate agreement, but asks MTR for more information. Plan was never announced to the public.

MTR asks contractors for proposal to complete project in 2015 based on partial-opening plan.

Government intends to tell Legislative Council of possible delay, but is stopped by MTR chief executive Jay Walder, who calls Transport Minister Professor Anthony Cheung Bing-leung and says deadline is still feasible. At Legco railways sub-committee meeting, Cheung's undersecretary Yau Shing-mu says major works can be finished in 2015, but tests and trials will take another six to nine months. After the meeting, MTR presents schedule towards completion to government, which says it is too brief.

Terminus contractors tell MTR that even with partial-opening plan, terminus will not be ready until June 2016.

Black rainstorm causes serious flooding in Yuen Long tunnel and damages tunnel-boring machine.

MTR and Cheung announce rail link will not open until 2017. Cheung says he is taken by surprise. Projects director Chew Tai-chong decides to retire early. MTR announces internal investigation.

Cheung sets up expert panel to investigate project and government's role. Panel chairman Professor Lee Chack-fan resigns because of conflict of interest.