Vermilion-Lloydminster MLA Richard Starke can continue to call himself a Progressive Conservative under the rules of the legislative assembly, the Speaker's office confirmed Tuesday.

Starke, who was first elected in 2012, is the only member of the PC and Wildrose caucus who did not join the new United Conservative Party on Monday.

He said he intends to remain a Progressive Conservative because he doesn't believe the new party will share his socially progressive values.

Interim UCP leader Nathan Cooper said Tuesday that a decision will be made about Starke's future in the next couple of days. But Cooper may not have a say.

Alex McCuaig, chief of staff to Speaker Bob Wanner, says there's nothing in the rules of the legislative assembly that can stop Starke from calling himself a PC in the legislature.

"He can self-identify as a PC MLA for the purpose of the assembly," he said. "There's a long history of members self-identifying their political affiliation."

For example, independent MLAs Ray Speaker and Walter Buck banded under the banner of the Representative Party in the early 1980s, McCuaig said.

McCuaig said Starke can keep calling himself a PC MLA even if the party doesn't want him or ceases to exist.

He noted Joe Clark continued to be a Progressive Conservative MP after the party merged with the Canadian Alliance to form the Conservative Party of Canada in 2003.

"It's not much different than Dr. Starke remaining a PC MLA," McCuaig said.

On Tuesday, Wanner officially recognized the 29 members of the UCP caucus as Alberta's official opposition. An overwhelming majority of members in the Wildrose and PC parties voted on Saturday to join under the UCP banner.

Cooper said he planned to talk to Starke about his decision to remain a PC and not join the UPC caucus.

"Hope to have a chat with him and hope to make a decision over the next couple of days," he said.