Xenophon influential in SA polling

High-profile senator Nick Xenophon could play a kingmaker role in a future South Australian election.

The latest Morgan poll showed the coalition would easily topple Jay Weatherill's Labor government, holding a 54-46 per cent two-party preferred lead.

However, gauging opinion of the Xenophon group for the first time, the poll put the group's primary vote at 18 per cent.

The coalition's primary vote stood at 37 per cent, with Labor on 26 per cent, Greens 10 per cent, Family First 5.5 per cent and independents/others 3.5 per cent.

The election is not due until March 2018.