Nationals MPs have been warned they should heed the concerns over climate change in their own communities ahead of the federal election, with internal research revealing the risk to the party in key electorates from a bitter Coalition split on coal-fired power.

The Nationals have been briefed on party polling showing that climate change is a key issue for voters in their federal seats, highlighting fears of a backlash in some electorates from a public crusade for coal.

Nationals leader Michael McCormack and deputy Bridget McKenzie have been caught up in a public debate with colleagues over coal power. Credit:Dominic Lorrimer

The research, presented to the federal Nationals MPs in Canberra last month, showed that voters were most concerned about the cost of living but that climate change also ranked as one of their top issues.

The findings are fuelling fears within the party about a backlash in Nationals strongholds in northern NSW and possibly other areas, where voters have increased their support for the Greens and independents.