Tony Abbott has been confronted by a furious Liberal voter and talkback caller who declared the Prime Minister the "world's worst salesman" and warned he was poised to hand the keys to the Lodge to Opposition Leader Bill Shorten.

An under-pressure Prime Minister used an interview on Fairfax radio station 3AW to warn his colleagues that the "one lesson" from the former Labor government was to not change leaders mid-term, while urging the caller, "Andrew", to help sell the government's reform message.

Mr Abbott declared it was "nonsense" to suggest he may not lead the Coalition to the next election.

Andrew described himself as a "Liberal voter through and through", but added: "I've got to be honest and truthful with you, Mr Prime Minster, you're on the nose with Liberal voters and that's a real concern to me because I don't want to see you give the keys to Bill Shorten at the Lodge.