The Greens are demanding an explanation from Clive Palmer about an apparent alliance with the Australian Sports Party's senator-elect Wayne Dropulich.
Fairfax Media reported on Tuesday that Mr Dropulich, who won a senate seat after the controversial recount in Western Australia, has been wooed by Mr Palmer's United Party and could join a senate voting bloc.
Mr Dropulich, a veteran gridiron player, is expected to attend Mr Palmer's speech to the National Press Club in Canberra on Tuesday, along with Australian Motoring Enthusiasts Party senator-elect Ricky Muir.
"Senator-elect Dropulich should outline to the people of WA the terms of any agreement he's reached with Mr Palmer, and what Mr Palmer has promised the Sports Party," Greens Senator Scott Ludlam said.
But any agreement with Mr Dropulich could prove premature, as the likely re-run of the senate election in WA looms.
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Former AFP Commissioner Mick Keelty is investigating what happened to the missing 1370 votes, which he confirmed changed the result, allowing the Greens and Mr Dropulich to win their seats.
A challenge to the Court of Disputed Returns has already been flagged by Mr Palmer, whose candidate Dio Wang was denied a seat by just 12 votes following the recount.
Mr Ludlam said an alliance between the two micro-parties would be an issue in any by-election.
"In a re-run of the WA senate vote, a vote for the Sports Party will be a vote for Clive Palmer," Senator Ludlam said.
