Lawmaker Tanya Chan challenged the chief executive in the last sitting of the legislative year, asking whether the Executive Council's principle of collective responsibility was eroding. Her question was prompted by Exco convenor Leung Chun-ying's repeated violations of this rule by commenting on government policies and challenging the administration. Chief Executive Donald Tsang Yam-kuen had no choice but to reply that the government welcomed different opinions; everyone, including Leung, had the right to express their opinions freely. After all, Tsang must convey a sense of unity and common purpose among top advisers and the administration. Leung immediately posted Tsang's comments on his blog, to prove that the government supports his actions. In fact, Tsang has criticised Leung for not abiding by Exco's rule of collective responsibility. Just because Tsang was not critical this time doesn't let Leung off the hook - because what he is doing is wrong. If he had a shred of integrity, Leung would take responsibility for his comments and actions and resign from Exco. That would save the government further embarrassment and give him total freedom to campaign for the chief executive's post. It's true that Leung's public comments and newspaper articles have drawn a lot of positive response. His recent article on Hong Kong's housing problems and policies was quite an eye-opener. His views on the minimum wage and competition law were straightforward and forceful - saying they were necessary to curb the widening wealth gap. Leung's arguments on those issues are judicious and sensible. Some of his points are not dissimilar to mine. If we didn't know he wrote them, they could easily be mistaken for policy blueprints from Civic Party member Alan Leong Kah-kit, for his own election campaign for the top post. Leung can certainly talk, but can he walk the walk? He has all along been highly critical of the government, but all his comments are made outside Exco. Why hasn't he voiced his discontent inside the council? He obviously wants his voice to be heard and his views reported by the media to increase exposure, raising his profile and popularity. Leung has already rolled out his campaign, taking advantage of every opportunity to comment on important social and economic issues - especially those concerning people's livelihood. At first glance his views on social issues may seem sound and reasonable. But we shouldn't forget that he is a member of the government's top advisory body, which is directly responsible for all those 'failed' polices that he so vehemently attacks. Shouldn't we question his motives and credibility for turning against his own kind? Clearly we should take his comments with a big pinch of salt. Talk is cheap but actions are expensive. If he plans to win the election by offering nothing more than shallow words, people who believe in him will be badly let down should he fail to follow through on his pledges due to political pressure. He would do well to remember that making empty campaign promises can have serious social and political consequences, such as social unrest. The most important qualities in a politician are credibility and the ability to undertake obligations and accept consequences. Leung shouldn't take political shortcuts for his own personal gain, or cast aside his obligations with no regard for political consequences. Many of us still remember the role he played during the Tung Chee-hwa administration. He was a top government adviser responsible for some of those wretched policies that brought down the property market. But he has never come out to claim responsibility for that miscarriage. Words from a politician with no credibility or integrity carry no weight. Political figures who think they can bend with the wind of popular opinion will not withstand the force of political storms. What a politician actually does is the key thing. Can Leung really afford to continue to play this political game? Albert Cheng King-hon is a political commentator