Speaking in a meeting of Panel on Constitutional Affairs, Ho said the government should not legalize same-sex marriage.

"This is a 'red line' that cannot be crossed,” he said.

He said mainland’s national security law stated the need to "prevent and resist the impact of harmful culture".

If the government goes towards the direction of legalizing same-sex marriage, “Would it violate our core values and interests of the country?" He asked.

Secretary for Constitutional and Mainland Affairs Erick Tsang Kwok-wai said the anti-discrimination measures are to promote integration and eliminate discrimination, but added he understood that some of the controversial issues need to be handled carefully.

"The community cannot reach a consensus on same-sex marriage, and we still have to listen to different views before proceeding with our work,” he said.