The star has found himself at the centre of the country's gay marriage debate after a backlash from conservative commentators who are unhappy he will perform the marriage equality anthem at Sunday's rugby league grand final in Sydney.

The singer arrived in Sydney on Saturday morning after a delayed departure from the US, before announcing his intentions.

Speaking to Channel Nine, Macklemore spoke about the power of music to bring a message to a wider audience and help effect change.

"[Using music to that end] is not to divide people, but create an environment where people can start a debate, can have a conversation - bring a message to the forefront," he said.

While the funding arrangement has not been formally worked out, he said the idea to donate to the "yes" campaign came to him in the car on the way to the media opportunity on Saturday.

"I haven't figured it out yet but I ... want to donate my portion of the proceeds from Same Love that I get off of that record here in Australia to voting yes."

Equality campaign co-leader Alex Greenwich said the financial support came at the critical halfway point in the debate.

"Macklemore's support and indeed his Same Love song continues to inspire and energise our campaign and we thank him for this generous support," he told AAP.

Australians were becoming increasingly tired of the negativity from the "no" campaign, Mr Greenwich added.

"I think we need more love songs, not less," he said.

"Same Love is a song which is about love and happiness and I think that's what Australians want to hear."

Macklemore has been pulled into the national marriage equality debate after it became known he would be performing the pro-marriage equality track at the NRL grand final.

An online petition started by former player Tony Wall to halt the half-time performance had been backed by former prime minister Tony Abbott, who tweeted that "Footy fans shouldn't be subjected to a politicised grand final. Sport is sport!"

Federal MP Bob Katter also slammed the NRL's decision to invite Macklemore to the grand final, claiming "nobody had ever heard of" the four-time Grammy Award winner.

Attorney-General George Brandis criticised Mr Abbott's selective backing of free speech and described calls to have the rapper's performance banned as "bizarre".

The recent publicity surrounding the song may have helped it surge up the Australian iTunes charts, where it stood at No.1 as of Saturday afternoon.

Macklemore initially appeared perplexed by the controversy, telling a US radio station he'd received "a lot of tweets from angry old white men".

"Imma go harder, Imma love," he told The Cruz Program.

The results of the national postal survey will be released on November 15.

Fairfax Media with AAP