Failed chief executive contender Henry Tang Ying-yen promised to accompany his wife - who was charged over an illegal basement at their home - to court, when the case is heard on March 13.
Tang, who was appointed to the Chinese People's Political Consultative Conference (CPPCC) a month ago, hinted that his family is "prepared" for any outcome of the trial.
Tang's wife, Lisa Kuo Yu-chin, was among four people charged last month over a 2,250 sq ft illegal basement at their house at 7 York Road, Kowloon Tong - while Tang himself escaped charges.
Revelations about the luxurious basement in the run-up to last year's chief executive election, together with Tang's handling of the scandal, dealt a fatal blow to his bid for the top job.
The charges could result in a jail term of up to three years and a maximum fine of HK$1 million, the Buildings Department said.
Tang responded to the prosecution for the first time, before leaving for the CPPCC meeting in Beijing this weekend.
"During the campaign for the [chief] executive, which I lost, I have gained the … full support of my family," Tang said.
"Therefore, I will support my wife when she goes for the first hearing on March 13. I will be there to support her spiritually, as well as physically."
He added that his family had become more united since the failed chief executive campaign.
When asked whether he was "prepared for the worst", Tang said "we have made adequate preparations … and I don't want to make further comments".
Tang said he now hoped to help shape mainland politics as a local delegate to the CPPCC, which is China's top political advisory body.
"This is the beginning of the [Beijing government's] 12th five-year plan. Hong Kong has a very special place in this plan, so I will be humble, observe [the CPPCC's workings] and make the best of this new opportunity for me to contribute to Hong Kong and the mainland," he said.
Tang is hotly tipped to be elected into the standing committee of the CPPCC, but he declined to comment on that yesterday. He said his experience as a former legislator and chief secretary, and his business network, would help him fulfil his role.