Support for Clive Palmer's United Australia Party is expected to keep Christopher Pyne's former seat of Sturt in Liberal hands.

The YouGov Galaxy poll prepared for The Advertiser has put Liberal candidate James Stevens ahead of Labor 53-47 per cent on a two-party preferred basis.

This is partly on the back of a surge in support for the UAP which is attracting about nine per cent of the primary vote compared to six per cent for the Greens.

The poll of 504 Sturt voters was taken on April 24 and puts primary support for Mr Stevens at 42 per cent and for Labor's Cressida O'Hanlon at 35 per cent.

Mr Pyne held Sturt for 25 years ahead of his decision earlier this year to quit politics and not stand at the May 18 election.

He retained the seat at the last election with a margin of 5.4 per cent.