Matt Canavan elected Nationals leader

The party room met at 10am to choose a successor after Mr Littleproud stepped aside on Tuesday afternoon, declaring he was "buggered" after nearly four years at the helm.

Its relatively small caucus of 18 MPs and senators meant only 10 votes were needed to secure the role.

The 45-year-old becomes the second Queensland-based leader of the party in succession and will face an early electoral test with a byelection in the NSW seat of Division of Farrer set down for May 9.

His elevation to the top job follows an unsuccessful challenge against Mr Littleproud following last year's bloodbath election result.

The deputy leadership was also spilled with Victorian MP Darren Chester emerging victorious.

Senator Canavan was elected to the Senate at the 2013 federal election and has been a key architect of the Nationals' policy platform over recent years and led its post-election review.

An outspoken former resources minister in the Turnbull government, he has been one of the Nationals' most vocal critics of Labor's renewable energy expansion, carbon markets and emissions policies and recent hikes in government spending.

His election signals the party room has opted for a combative approach as the Coalition rebuilds following last May's election defeat and faces a resurgent One Nation across regional Australia.

The leadership has traditionally carried the deputy prime ministership when the Coalition is in government, making it one of the most influential roles representing regional Australia.

However, the party's decision to base its leader in the Senate and not alongside Liberal leader Angus Taylor in the lower house following two recent splits in the Coalition, where he would be able to take on the government face to face, was a key point of party room contention.

While the Nationals have somewhat alternated leadership across state branches, only Mr Littleproud, who took over in 2022, and Warren Truss, also from Queensland, have broken a run of party leaders from NSW stretching back to Doug Anthony in the 1970s and including Ian Sinclair, Tim Fischer, John Anderson, Mark Vaile, Barnaby Joyce and Mr McCormack.

The ballot set by Chief Whip Michelle Landry less than a day after Mr Littleproud resigned caught some party room members off-guard.

Senator Canavan resigned from cabinet in 2020 to throw his support behind an ill-fated leadership bid by Barnaby Joyce but remained as the party's deputy leader in the Senate.

The traditionally conservative electorate of Farrer was vacated by the retirement of longtime MP Sussan Ley, polling released on Wednesday has the Liberals sitting at 16 per cent and the Nationals at five per cent in an early snapshot published on Wednesday.

Michelle Milthorpe, running as a Climate 200-backed independent, polled at 28 per cent and David Farrer of Pauline Hanson's One Nation at 26 per cent.