EDMONTON -- Alberta's legislature speaker apologized on Monday after he and 16 MLAs denounced the province's latest COVID-19 restrictions last week.

On Monday morning, Premier Jason Kenney was asked if Speaker Nathan Cooper could "effectively moderate debate" after he made his stance on restrictions known in a signed letter last week.

"The neutrality of the speaker is an essential aspect of our parliamentary system," Kenney answered. "The speaker must be both neutral and seem to be neutral, which is why the longstanding tradition that goes back hundreds of years is for the speaker to avoid taking positions on current and contentious political issues, because the speaker does a responsibility to represent that whole house and not a faction of the assembly.

"The longstanding convention, of course, is for speakers to scrupulously maintain their neutrality, and in my 24 years as a parliamentarian I cannot ever recall a speaker ever violating that until last week."

Later that day, Cooper said he regretted the error.

"I apologize to each and every one of you for crossing a line that the speaker ought not cross," Cooper told MLAs at the legislature.

"I can assure my colleagues that I have taken significant learnings from this event and I recommit to you to give you my best at every turn, and I apologize unreservedly."