He has spent about 50 hours listening to debate over the budget bill, but Legislative Council President Jasper Tsang Yok-sing says he needs "a better reason" to end the filibustering.
Lawmakers have been vetting the bill since April 30, but it is still only on the third of five sections of the debate.
The government has repeatedly warned that its reserves will dry up if Legco fails to pass the bill by the end of May. Yet Tsang says that is not a good enough reason to push through the debate on the 1,192 amendments tabled mainly by four radical pan-democrats. "If the members have fully followed the rules of procedure, I must allow them to speak," said Tsang, who on Friday took time out from the filibuster to celebrate his 65th birthday, which was yesterday.
"Is there any reason for me to halt the debate to pre-empt the lawmakers wanting to speak? It is something I have to consider."
But Tsang bemoaned the fact that a quarter of the meeting time had been wasted determining whether a quorum had been met.
He said he must comply with the Basic Law and rules of procedure when considering stopping the debate. He hoped voting could be finished in two weeks.
On warnings by officials of a "fiscal cliff" if the bill is not passed this month, he said the government "would handle the issue".
Financial Secretary John Tsang Chun-wah on Thursday said the government would suspend funding for the Legco Commission, the Hospital Authority and the University Grants Committee next month because of the budget bill filibuster.