The Nationals Senate leader Bridget McKenzie has been restored to cabinet and Darren Chester has been dropped to the backbench in a reshuffle of blatant reward and punishment following Barnaby Joyce’s elevation.

The reshuffle comes as Newspoll, published in The Australian, shows the Nationals’ turmoil and problems with the vaccine rollout have had little impact on polling numbers.

Labor went to a 51-49% two-party lead, compared with a 50-50 result in the previous poll. But the Coalition primary vote was stable on 41% while Labor improved one point to 37%. Both leaders had small improvements in their satisfaction ratings. There was little change on the measure of “better PM”, where Scott Morrison leads Anthony Albanese 53-33%.

In the reshuffle Andrew Gee, whose switch to Joyce was important in his victory, goes from the outer ministry into Chester’s cabinet spot, and his portfolios of veterans affairs and defence personnel. Chester had been an outspoken supporter of ousted leader Michael McCormack.

McKenzie becomes minister for regionalisation, regional communications and regional education, as well as minister for drought and emergency management. It had been speculated that she wanted responsibility for agriculture.

Deputy leader David Littleproud retains agriculture but loses emergency management while gaining responsibility for northern Australia. He will retain a stake in the policy side of drought, which he previously had responsibility for, through his agriculture job.

It is something of a slap for Littleproud – who would have run for leader if McCormack had not stood – given his deputy position. Emergency management has a high profile.

Keith Pitt keeps resources and water but is dropped to the outer ministry and loses responsibility for northern Australia. Questioned about the demotion of mining to the outer ministry Joyce said Pitt would remain “over this portfolio like a bad suit”.

The very political nature of the changes, with their paybacks, risks reinforcing the divisions that have plagued the Nationals.

In the Coalition, the Nationals leader chooses their team but has to negotiate with the prime minister on portfolios. In this reshuffle the Nationals have not been able to encroach on any portfolios held by Liberals.

The changes were announced by Scott Morrison.

Morrison forced McKenzie’s resignation in early 2020 in the wake of the sports rorts affair.

Morrison said McKenzie would have “a clear focus on service delivery in regional Australia and be responsible for the continued work developing Australia’s disaster management capability”.

David Gillespie joins the ministry as minister for regional health, and will be deputy leader of the House, a post Chester held. Mark Coulton is relegated from the junior ministry to the backbench.

Kevin Hogan will be assistant minister to Joyce, as he was to McCormack, and becomes assistant minister for local government.

Michelle Landry continues as assistant minister for children and families, but loses her previous post of assistant minister for northern Australia.

Outside the formal executive senator Susan McDonald, from Queensland, another Joyce supporter, has been given the role of “envoy for northern Australia”.

Morrison said: “These changes will provide the strongest female representation in an Australian government cabinet on record, building on the previous record also achieved under my government”.

One of Joyce’s political problems is seen to be the opposition from significant women in the rural community, as well as the doubts about him from some within his party given that a claim (which he rejects) of sexual harassment was key to his resignation from the leadership in 2018.

Chester said in a statement: “I will continue to advocate strongly for Australians to understand that the majority of veterans will transition successfully to civilian life. The myth that all veterans are broken is damaging to their well-being and creates a vicious circle of despondency and desperation.

"As a grateful nation, we must support those who need our help but at the same time promote the many achievements of our veteran community.”

Labor’s shadow minister for resources Madeleine King and shadow minister for Queensland resources Murray Watt said the government “has delivered a slap in the face to mining and resources communities around Australia by dumping the portfolio from cabinet”.

The limit of Joyce’s clout was shown at the weekend when one of his supporters, Northern Territory senator Sam McMahon, was defeated for preselection by Jacinta Price, an indigenous woman who is Alice Springs deputy mayor.