Despite a plebiscite on marriage equality being rejected by the Senate last year, this week's Budget allocated $170 million to the divisive government policy.

In Buget Paper No. 1, finance for the same-sex marriage plebiscite is listed as "unchanged".

"The Australian Government remains committed to a plebiscite in relation to same-sex marriage, despite the Senate not supporting the Plebiscite (Same-Sex Marriage) Bill 2016," the 2017-18 Budget states.

"To this end, the Australian Government will provide $170 million to conduct a same-sex marriage plebiscite as soon as the necessary legislation is enacted by the Parliament."

The bill was introduced to Parliament in November 2016, but was blocked in the Senate when Labor, the Greens, Derryn Hinch and the Nick Xenophon Team voted to reject the bill 33 votes to 29.

Numbers aren't changing: Senate said no to a plebisicite & yes to a parliament vote. Time for our MPs to make history & make people happy. https://t.co/kGYqo90PmZ — Alex Greenwich MP (@AlexGreenwich) May 10, 2017

Liberal party members at the time said rejection of the plebiscite would delay marriage equality in Australia by several years.

Deputy Opposition Leader Tanya Plibersek said this Budget "has brought the marriage equality plebiscite back from the dead".

"Despite explicitly banking more than $100 million in savings for not proceeding with the marriage equality plebiscite in last year’s mid-year economic and fiscal update, $170 million in funding for the marriage equality plebiscite has reappeared in the 2017-18 Budget as a contingency measure," she said.

She said the plebiscite was met with strong opposition from Labor and the Greens because it would cause unnecessary pain for the LGBTI community.

"The message to the government was clear – just get on with a free vote," she said. "Don’t put LGBTI Australians through a painful, unnecessary and expensive plebiscite.

"Prime Minister Turnbull needs to explain why the government has made a screeching reversal on its funding allocation for a plebiscite – is he planning on proceeding with Peter Dutton’s ridiculous idea of a postal vote plebiscite?

"If not, why bring the funding back to the Budget?"

It is unclear whether the government plans to reintroduce the bill to parliament.

ICYMI Malcolm Turnbull hid a plebiscite for #marriageequality deep in the budget papers. I wanted to share this quick message with you. pic.twitter.com/bM6w4cBJIw — Tanya Plibersek (@tanya_plibersek) May 10, 2017

THE FEED (2016): Love & Marriage in Australia