A mutiny against Deputy Prime Minister Barnaby Joyce is now in the open, with backbencher Ken O'Dowd speaking out on his way into Parliament this morning.

Key points: LNP's Ken O'Dowd is openly canvassing for the Deputy PM's replacement

LNP's Ken O'Dowd is openly canvassing for the Deputy PM's replacement Backbencher David Littleproud says critics should "put up or shut up"

Backbencher David Littleproud says critics should "put up or shut up" Nationals whip Michelle Landry says Mr Joyce should get more time

The ABC reported yesterday a delegation of Nationals MPs is being organised to visit Mr Joyce and tell him to stand aside.

Mr O'Dowd confirmed to journalists this morning that Mr Joyce "needs the advice" and "someone needs to tell him where the party stands".

"I would prefer it to be two or three people," Mr O'Dowd said.

Ken O'Dowd said he wanted the Nationals leadership matter sorted out today or tomorrow. ( www.kenodowd.com.au )

He said he wanted the matter resolved today or tomorrow.

But Nationals Cabinet member David Littleproud demanded Mr Joyce's critics should "put up or shut up".

"There is no leadership to be resolved," Mr Littleproud told AM.

David Littleproud is one of Mr Joyce's strongest allies, especially after being promoted to Cabinet from the backbench last December.

Mr Joyce's future is in doubt because of the public backlash Nationals are facing from their constituents about the way he has handled his marriage breakdown and new relationship.

He is now expecting a baby with his former media adviser.

Nationals president Larry Anthony is in Canberra to deal with the crisis, which he called a "very difficult time" for the party.

"But the National Party always works through these issues," Mr Anthony said.

"That is why I am down here today."

Sorry, this video has expired Barnaby Joyce publicly apologised on Tuesday for the hurt caused by his affair.

'I think we need to give him a fair go'

More Nationals have spoken out in defence of their leader today.

Backbencher George Christensen said only a small number of his colleagues wanted Mr Joyce to step aside as leader, and said they did not have the numbers to succeed.

"To be honest, there is a small number of people, sadly in the National Party, probably more people in the Liberal Party, who are talking about internal politics and leadership," Mr Christensen said.

"I am not interested in talking about that, people get sick and tired of hearing about these internal games."

Deputy Nationals leader Bridget McKenzie said Mr Joyce had the full support of the party.

Nationals whip Michelle Landry also backed Mr Joyce, saying "Barnaby will remain our leader".

She said he should be given more time.

"He has done a lot for us particularly in regional Australia and I think we need to give him a fair go with it," Ms Landry said.

Ms Landry said Mr Joyce's personal life should be a consideration.

She said as far as she was concerned, "everything was above board with his office", referring to the questions raised about his travel arrangements.

Sorry, this video has expired Michelle Landry told reporters on Wednesday Barnaby Joyce still had the party's support.

But Mr O'Dowd is openly canvassing who could replace Mr Joyce as leader and Deputy Prime Minister.

"We've got plenty of people in the Nationals party room, a lot of capable guys there, and if it comes to that we would find a good leader, I feel sure about that," Mr O'Dowd said.

Mr Joyce is due to be acting prime minister next week when Malcolm Turnbull travels to the United States.

Foreign Minister Julie Bishop said she was prepared to cancel her travel plans and fill the role instead if Mr Joyce stepped aside.

"I am returning to Australia from Kuwait and I do have plans to be overseas next week, Parliament is not sitting, if circumstances change then of course, I would change plans," Ms Bishop said.

While Ms Landry is strongly defending Mr Joyce to stay on as leader, she indicated he might not be acting Prime Minister next week.

"We will wait and see what happens with that, he has got decisions to make and I think we need to let him have a bit of personal time to sort this out," Ms Landry said.

"It is stressful, marriage break-ups are very stressful things to go through and I think he is here to stay."