Support from an eighth of nominating committee members could be a possible threshold for aspirants to enter the chief executive election under universal suffrage, Elsie Leung Oi-sie says.
Pan-democrats have suggested retaining for the 2017 chief executive election, the first under universal suffrage, the one-eighth threshold used for last year's election.
Leung, vice-chairwoman of the national legislature's Basic Law Committee, also said making it a legal requirement that candidates "love the nation and Hong Kong" and "not be confrontational to Beijing" would contravene the Basic Law and the Bill of Rights.
Qiao Xiaoyang, chairman of the Law Committee of the National People's Congress, who listed the two requirements in March, had earlier said there was no need to make them legal requirements.
Leung, a former secretary for justice, made her remarks in a pre-recorded interview with Democratic Party chairwoman Emily Lau Wai-hing, to be webcast on Friday on online media platform OurTV.
Leung said the idea of requiring an aspirant to gain support from an eighth of the nominating committee, whose members have yet to be determined, would be worth considering.
Qiao's remarks - in which he also said the nominating committee should decide collectively, not individually, who could stand - sparked concerns from pan-democrats that the threshold could be set too high for them to compete. Asked if the threshold could be set at 10-plus per cent of the committee, Leung said: "It is one of the proposals but it remains unknown how many proposals will be put forth."
Pressed on whether requiring support from 60 to 70 per cent of members would be an "unreasonable restriction", Leung said: "It won't be 60 to 70 per cent."
The NPC Standing Committee had stated that the composition of the nominating committee could draw reference from the existing chief executive election committee, she said, adding: "Our Election Committee has never imposed such a rule."
Leung said writing Qiao's two requirements into law "would contravene the Basic Law, which stipulates that all should be equal before the law".
It would also breach Article 1 of the Hong Kong Bill of Rights.
However, Leung disagreed with the suggestion that the city's political reform was no business of the central government. She said Beijing had a role to play in Hong Kong's political development given the importance of the political system.