Freedom of expression and of the press are the cornerstones upon which Hong Kong's success has been built and maintained. However, the foundations are not as solid as they seem. The fact that confidence is shaken whenever these freedoms are called into question underlines the need for vigilance. The concerns raised from the sacking of outspoken radio talk-show host Li Wei-ling are understandable. She had worked for Commercial Radio for nine years and is known for her critical stance towards the government. Given the current political atmosphere, it is to be expected that her dismissal is seen by some as politically motivated. The veteran journalist noted that there were suggestions that the sacking might be due to discord with the management or commercial reasons. But she was convinced that it stemmed from suppression by Chief Executive Leung Chun-ying. She said someone close to Leung had warned her to "mind her job" though she stopped short of identifying that person. Referring to some private conversation with her former boss, Stephen Chan Chi-wan, and work changes over the past year, she said the broadcaster had bowed to political pressure in the run-up to negotiations over its licence renewal and sacked her. But Leung swiftly denied he had ever mentioned to anyone any matters related to Li's position or work. Chan also rebuked Li's allegations in his radio programme. But that does not clear the air. Some lawmakers demand a Legco inquiry into the saga. This is not the first time the broadcaster has been embroiled in such controversy. A top executive of the broadcaster yesterday dismissed Li's accusation as unfounded, adding that it had caused grave damage to Hong Kong. But she would only say the basis of trust and co-operation with Li had been destroyed, without elaborating further the reason for Li's dismissal. The response falls short of expectations of a broadcaster licensed to use public airwaves. The allegations levelled against the chief executive are serious. But the evidence produced so far has yet to prove that Leung was behind the sacking. More concrete evidence is needed to substantiate the claim. Leung's pledge to uphold press freedom is to be welcomed. However, confidence in freedom of the press and freedom of expression is so fragile that it takes more than mere words to ease public worries. The government, the media and society have the duty to ensure our freedoms are not eroded.