Lawmakers from today are no longer allowed to move amendments to amendments in discussion of non-binding members' motions.
The change to a rule that has existed since 1993 was adopted by the Legislative Council rules of procedure committee after being proposed by pan-democrat Kenneth Leung Kai-cheong.
Leung insisted his move was not an attempt to limit freedom of speech but was instead aimed at simplifying an often complicated system.
"I hope the change can help bring the focus back to work," the accounting-sector lawmaker said.
"Some said the rule change limits colleagues' chances to express their views … but amendments to amendments are often moved because a shorter notice period is required," he said, noting that amendments required five days' notice while amendments to amendments needed only three.
The last amendment to an amendment was tabled by Federation of Trade Unions lawmaker Wong Kwok-kin last week, on Lee Cheuk-yan's amendment to the motion of thanks for the chief executive's policy address.
The Beijing loyalist sought to water down the pan-democrat's amendment which "regretted" the chief executive's failure to fulfil an election promise. The motion of thanks was voted down.
"Amendments to amendments multiply the combinations entailed in the members' motions, complicating the scenario," Leung said.
"Former lawmakers remember that back then when motions were tidier and neater, officials did follow up on approved members' motions."
Citing foreign examples, Leung said he also wanted to put a word limit on members' amendments to motions and bills and on officials' speeches.
"The UK Parliament has clear rules regarding speeches - officials' initial replies to members' questions cannot exceed 75 words," Leung said.
None of the implemented or proposed changes would have any effect on the hotly debated topic of filibustering.
Leung suggested the Legco president should be allowed to raise a closure motion only when the amendments to the government bill under discussion were "trivial and repetitive".
The debate should then be halted only if the closure motion got a majority vote in both the functional and geographical constituencies.
The longest filibuster was led by radical democrats on the old-age allowance. The Finance Committee spent almost two months in 2012 going through more than 1,200 amendments before approving the government's application to double the allowance for needy elderly.