Saturation point - for the trains and for Leung's man Cheung Chi-kong

Government adviser Cheung Chi-kong is not one to back down. But over the weekend he was forced into an embarrassing apology for claiming that a record number of workers - not mainland visitors - was to blame for overcrowding on the trains.

The Executive Council member had been pilloried for saying at a forum last Monday that those who blamed the rising number of mainland visitors for crowding on the MTR had reached the "wrong conclusion". Cheung, 56, told the forum: "People complain that mainland travellers are making our traffic very busy.

"But a major reason is that the number of employees [in Hong Kong] has risen by more than 100,000 over the past two years."

The remarks come at a time when some 40 million mainlanders visit Hong Kong every year - a number that is expected to reach 100 million by 2020. Chief Executive Leung Chun-ying's administration is grappling with heightened social tensions created by this influx - including the plight of annoyed commuters who struggle to get on trains.

Cheung eventually conceded that mainland visitors also contribute to the crush and admitted he had "oversimplified the problem". In an interview with TVB on Saturday, he said he had meant to say the growing number of mainland visitors was not the only reason for crowding on trains: "I was careless and did not make myself very clear. For this, I apologise."

Dr James Sung Lap-kung, of City University, who has known Cheung a long time, said he rarely conceded a point. "He is the kind of person who will spare no effort to win [an argument]," Sung said. "He is a talkative man. He likes to talk a lot and get his point across.