The Liberal-National coalition is "rock-solid" despite the High Court citizenship ruling upsetting the balance within government, senior frontbencher Darren Chester.
The Nationals MP accepted that Barnaby Joyce and Fiona Nash were responsible for breaching the constitution, but was confident the loss of the National Party leaders would not upset dynamics in the joint party room.
"We have a rock-solid relationship with our senior Liberal colleagues," Mr Chester told the ABC on Saturday.
A long-awaited High Court judgement on Friday ruled the Nationals leader and deputy leader ineligible to sit in parliament for being dual-citizens at the time of their nomination.
Longstanding coalition arrangements see alternating positions of seniority shared between the Nationals and Liberals, with a Liberal prime minister at the top of the chain.
The loss of the top two National leaders on Friday and Malcolm Turnbull's planned trip to Israel has throw that leadership hierarchy into question.
But for now, the Nationals are focused on a by-election for Mr Joyce's seat of New England on December 2.
Mr Chester said it was less clear how Fiona Nash will be involved in public life in the future.
"That is a disappointment for me. She is a close friend and is successful in standing up for regional Australia," he said.
The parliamentary National Party team voted yesterday to elect frontbencher Nigel Scullion as an interim parliamentary leader.
But Mr Chester said: "If you are looking at it as a question of who is the overall figure of seniority in the public eye, it is Barnaby Joyce."
The role of deputy prime minister will likely remain vacant until the result of the New England by-election becomes known.
Meanwhile, Labor's Penny Wong said the government was in "utter chaos" and should disclose details of the Liberals-Nationals agreement about who will serve as acting prime minister when Malcolm Turnbull leaves for Israel.
"There is an unseemly fight between the National Party and the Liberal Party over who will be the acting prime minister... Another reason why Malcolm Turnbull should stop making that document secret," Senator Wong told ABC Radio on Saturday.