Joyce's recently-elected deputy, Bridget McKenzie, who had been previously silent, told Sky she'd give "my absolute rolled gold guarantee ... that come tomorrow, come Friday, Barnaby Joyce will be leading the National Party".
Former senator Jacqui Lambie on her first day in Parliament in 2014.
Yesterday members of the Nationals Party were reportedly deciding whether there was enough divide in the party to ask for Mr Joyce's resignation, in the wake of a growing number of questions surrounding the Deputy Prime Minister's alleged affair with former media advisor Vikki Campion.
NSW Nationals MP and Veterans Affairs Minister Michael McCormack last night denied the party was discussing a possible replacement, while others suggested Mr Joyce could survive.
"There's a lot more stuff that's going on they could be talking about that's more important to the damn country than whacking this out - but this is the way their advisers handle things too", she said.
The deputy prime minister apologised to colleagues at the regular Coalition party-room meeting, and made a public statement of regret to his estranged wife, Natalie, his four daughters, to his former staffer and now pregnant partner, Vikki Campion, and to voters in New England.
The same proportion said they would have been less likely to vote for Mr Joyce had they had know the details before last year's byelection.
Mr Joyce has denied breaching the ministerial code of conduct.
But Nationals Cabinet member David Littleproud demanded Mr Joyce's critics should "put up or shut up".
As pressure appeared to ease for Mr Joyce to stand down, or be replaced, Ms McKenzie said she backs Mr Joyce "110 percent".
Nationals president Larry Anthony is in Canberra to deal with the crisis, which he called a "very hard time" for the party.
KEITH Pitt is believed to be part of a delegation set to approach Nationals leader Barnaby Joyce today about his future.
He argued Ms Campion was not his partner when she worked in his and Matt Canavan's office.
Barnaby Joyce has secured his colleagues' backing to hang onto his leadership and Malcolm Turnbull has flagged he will be acting prime minister next week, despite the potential for this to cause further distraction for the government.
Foreign Minister Julie Bishop said she was prepared to cancel her travel plans and fill the role instead if Mr Joyce stepped aside. "If circumstances change then of course I would change my plans, but that's not my understanding".
Figures released on Thursday showed between January 1 and June 30 past year Mr Joyce's work flights on government planes, which also included periods when he was acting prime minister, totalled $227,508.