Act Party leader David Seymour this morning launched a scathing attack on both Winston Peters and the Greens.
Seymour told Newshub that Green MP Marama Davidson was the "wild card that will bring down this Government".
"It's only a matter of time before she is anointed as the Green Party co-leader. She doesn't play by the rules that most politicians do. She will make Metiria Turei look like a sensible version of Helen Clark," Seymour said.
He went on to repeat his description of New Zealand First leader Winston Peters a "charismatic crook".
"With no hints on policy, and vague attacks on 'capitalism', New Zealanders now face a weak left-wing coalition beholden to a madman on the loose," he said in a press release.
"Winston Peters' perverse marriage with Labour and the Greens threatens countless groups: taxpayers, Auckland infrastructure users, millennials, immigrants and the businesses relying on them, and more.
"The silver lining for the centre right is that the three-ringed circus is likely to fall apart - perhaps even before its three years are up. The Greens and New Zealand First despise each other, and Winston Peters has caused chaos in every government he's joined. New Zealanders may face an election sooner than they think."
Seymour told Newshub NZ First did not have "the depth of talent" to fill the four ministerial roles they had been promised.
"We in New Zealand have had an election on a three-year time frame like clockwork since World War II... but the most serious challenge to that has been elected last night."