The confrontation was over the delay in the project to extend the underground train system.

The issue of the underground rail project was brought up by caretaker Prime Minister Thaksin Shinawatra, who said it was behind schedule. Pongsak, who oversees the Mass Rapid Transit Authority of Thailand (the operator of the underground train system), said the delay was caused by a former transport minister, referring to Suriya.

In apparent frustration, Suriya stood up and explained that the factors leading to the delay were out of his hands, before vowing to take responsibility for any setback caused by the delay. He then walked out of the meeting.

Thaksin reportedly attempted to persuade Suriya to stay on, but failed. The Thai Rak Thai leader then set up a special meeting to discuss the project tomorrow.

There have been rumours that Suriya, also the industry minister, was planning to resign from the ruling party even before yesterday's walkout.