Former premier warns against plebiscite

The Turnbull government should abandon a plebiscite on same-sex marriage and let parliament decide, former NSW Liberal premier Nick Greiner warns.

He says having the prime minister and deputy Barnaby Joyce on opposite sides of the public vote - first promised by Tony Abbott - will do nothing for coalition stability.

"A re-elected coalition spending its first six months diverted and divided by a plebiscite is not in anyone's interest, much less the nation's.

"Indeed, it should fill us with horror," he wrote in The Daily Telegraph on Thursday.