This came as the election for Hong Kong deputies to the National People's Congress is set to be held next month, with sources saying that one-third of the current 36 members will step down from their post - including 72-year-old Tam.

There is no age limit on election candidates, but common practices will see those aged 70 and above stepping down. Including Tam, around a dozen current members have reached 70 or above.

Sources said the pro-Beijing heavyweight told his party members earlier that he would not seek re-election. Meanwhile, Tam told Sing Tao Daily - The Standard's sister publication, that he would announce his decision on coming Monday.

As to who would replace Tam to become the city’s next sole delegate to the top legislative body, rumor has it that former chief executive Carrie Lam Cheng Yuet-ngor would gun for the spot.

It is understood that the successor must be a political heavyweight trusted by the Central Government and is familiar with Hong Kong and mainland affairs.

According to sources familiar with Lam, being a vice chairwoman of the Chinese People's Political Consultative Conference holds a higher status than being a member of the National People's Congress Standing Committee, which Lam may still hesitate to make a move.