On Tuesday veteran pro-establishment legislator Paul Tse Wai-chun told government radio that his camp felt discontented with Cheng.

“Other members from the pro-establishment camp have started to feel impatient and discontent,” Tse, who is not affiliated with a party, said. “It seems there aren’t many words that we can say [in defence of Cheng].”

Asked if he would support the idea of asking Cheng to resign, Tse did not answer directly but suggested that could be an option if certain conditions were met.

“I would like to see if she has any more explanations and whether there are factors that we have to consider. At the moment, if I can’t see any of these important factors, of course I am inclined to feel that short-term pain is better than long-term suffering,” Tse said.

Cheng had given the public an impression that she was finding different excuses for her situation, which could undermine the government’s authority, he added.

One in four Hong Kong properties has illegal structures, but most owners get away with their misdeeds

Pro-establishment lawmaker Michael Tien Puk-sun warned that Cheng needed to step down if it was proved that she had commissioned any of the illegal structures herself.

“If Cheng avoids the legislature and refuses to explain herself here, this controversy can’t be resolved. It would do her no good,” he said.

Liberal Party leader Felix Chung Kwok-pan said he noticed that some lawmakers in his camp had “turned critical” of Cheng.

“We welcome her to come and explain any time,” Chung said. “She needs to bear in mind that the situation could worsen if things drag on for too long.”

Speaking on condition of anonymity, another pro-establishment legislator said: “There is a general feeling in the camp that Ms Cheng’s position is untenable, especially in light of further disclosures that her basement is well equipped ... Her integrity is in question.”

The legislator was referring to media reports that the basement of Cheng’s house in Tuen Mun had a band practice room and a storeroom.

Chinese University political scientist Dr Ma Ngok noted that since Sunday the two largest pro-establishment parties in Legco – the Democratic Alliance for the Betterment and Progress of Hong Kong and the Business and Professionals Alliance – had been reluctant to defend Cheng.

“I believe that the biggest problem is that they don’t know how much more information is going to be exposed and how bad the fiasco is going to get ... even [Chief Secretary] Matthew Cheung did not know how to defend his colleague either,” Ma said.

Cheung said on Tuesday: “Ms Cheng has already made it clear that she was not sensitive enough in handling the matter, and that she is certainly doing her best to rectify all the problems, particularly the illegal structures concerned.”

He also noted that Cheng had apologised repeatedly for the “inconvenience and concern caused in the community”.

Cheng will attend Legco’s weekly meeting on Wednesday to answer accountancy lawmaker Kenneth Leung’s question on criminal prosecutions. It was unclear on Tuesday whether she would take the opportunity to answer questions about her properties.

Civic Party legislator Dennis Kwok said his party had asked for a special meeting at Legco for Cheng to come clean. If she kept avoiding addressing lawmakers, the pan-democrats would have to move a motion of no confidence against her, or a motion invoking the legislature’s special power to look into the matter, he said.