Howard to hit campaign trail with Joyce

Former prime minister John Howard is willing to hop on the campaign trail to help Barnaby Joyce retain his seat in parliament.

The Nationals leader is facing a challenge from independent Tony Windsor in New England, with early polls showing the race will be tight.

"I've spoken to Barnaby Joyce and I'll be very happy to go there and campaign for him and he'll certainly be very happy for me to do so," Mr Howard said on Thursday.