Both say regardless of what the Liberals do they are going to work hard to ensure the alliance and government work, but they will not say how they will handle the issue of Speaker until it comes up in the house.
Meanwhile, Weaver said Clark is playing games by insinuating the Liberals would only keep a Speaker as long as they are in power.
"That's freakish commentary, and there is absolutely no authority whatsoever for that proposition", said de Jong, holding up a textbook of parliamentary practice.
"Our message today is quite clear and categorical", NDP Leader John Horgan said.
It's an important issue because the two parties - with 41 NDP MLAs and three Greens - hold a slim one-vote edge over the 43 Liberals in the legislature.
The NDP's Mike Farnworth, who has served as Opposition house leader for years, said the NDP-Green alliance will provide stable government with or without a Liberal MLA in the Speaker's chair.
"The practical workability of that agreement is very much in doubt", he said.
Weaver changed his position on the need for a B.C. Liberal speaker on Thursday, arguing that the alliance could function even if it put forward an NDP MLA to preside over the legislature.
Horgan said the paralysis of government since the start of the election campaign in April is hurting the economy and stability of the provincial government. The Green Party ran on a principled approach to governing in B.C., a sentiment that resonated with many British Columbians, including some in Powell River-Sunshine Coast.
As to the complaints that government isn't reconvening fast enough, De Jong said the legislature is not meeting any later than it normally does after other May elections. "The whole issue of the Speaker is irrelevant", he said.
Once a Speaker is selected, de Jong says a priority will be to deliver the throne speech, followed by the required debate before the expected confidence vote for the Liberal government.
The institute says it based its findings on the Greens' pledge to "roll MSP payments into the payroll tax and personal income tax" and the NDP's intent to "replace the lost revenue with increases in other taxes".