Lambie proposes triple treat plebiscite

Independent senator Jacqui Lambie wants the same-sex marriage plebiscite to be held alongside a referendum on constitutional recognition and euthanasia.

Jacqui Lambie wants recognition, euthanasia and gay marriage plebiscites held on the same day. (AAP)

Money could be saved by having a same-sex marriage plebiscite on the same day as a referendum on constitutional recognition of indigenous Australians, as well as euthanasia for the terminally ill, a crossbench senator says.

Independent Jacqui Lambie cites Parliamentary Budget Office advice she's received showing all three could be done for the price of two.

"Why can't we leave it until about September next year," she asked reporters in Canberra on Tuesday.