Chief Executive Leung Chun-ying wrote to Jasper Tsang Yok-sing reminding him to "take lawmakers' unruly behaviour seriously", the Legislative Council president disclosed yesterday.
The letter was sent on May 21, a day before one of the chief executive's quarterly question-and-answer sessions.
Several lawmakers had shouted insults and thrown objects at officials, disregarding council rules and officials' dignity, Leung wrote. He appealed to Legco to take the matter seriously and condemn any misconduct.
Despite the letter, the Q&A session was called off prematurely as radical lawmakers hurled insults, prompting Chief Secretary Carrie Lam Cheng Yuet-ngor to write a second letter to Tsang repeating Leung's demands.
Tsang said yesterday that he replied to Lam's letter on Friday, saying he found it "regrettable" that the session was disrupted.
In his reply, he stressed that the executive and legislature had different functions but shared the common goal of serving Hong Kong people.
"In pursuance of this goal, I expect the executive and the legislature to enhance communication in matters of mutual concern," Tsang wrote, hinting that the executive had a role to play in improving the relationship between the two.
In conclusion, he wrote that unless Legco's rules of procedure were amended, its president could not prevent misconduct and could only take action once misconduct had occurred.
Tsang said yesterday that after receipt of the letter, he discussed the conduct of the Q&A session with the Legco Secretariat.
Tsang said Lam had previously written to him voicing the government's views on the goings-on in Legco.
Still, he hinted it was unusual for the chief executive to write specifically about the handling of the Q&A session.
Tsang's predecessor Rita Fan Hsu Lai-tai said the Legco president had to comply with the rules of procedure.
"The Legco president cannot change his mode of holding meetings - which has to follow the house rules in accordance with the Basic Law - just because of certain pressure," said Fan, a member of the National People's Congress Standing Committee.
On Thursday, it was revealed that the Financial Services and the Treasury Bureau wrote to Finance Committee chairman Ng Leung-sing on May 22 asking him to make use of a meeting rule to kill members' motions.
The move was aimed at heading off a filibuster planned by radical pan-democrats, including Leung Kwok-hung of the League of Social Democrats. Leung condemned the letter as "brutal interference" in Legco affairs by the government.