Two Melbourne women have been given legal approval to tie the knot before Christmas, which means Australia’s first same-sex marriage will happen sooner than expected.

Megan Stapleton and Stephanie Dybal have been together for more than five years and organised a non-binding wedding for 21 December, well before laws were passed by federal parliament.

When Canberra inked the legislation, a mandatory four-week wait meant the first nuptials were on track for 9 January.

But because Stapleton and Dybal had been preparing their wedding for months and had relatives flying in from overseas, they were granted approval to go ahead with their plans legally.

“They have family flying down and had everything booked and paid for back in May when no one thought the law was going to change … so Births, Deaths and Marriages approved it,” their wedding celebrant and gay rights activist Jason Tuazon-McCheyne said on Thursday.

“This is by no means a stunt, and they had no desire to be the first couple, it just happened that it was all booked.”

It may be the case that other Australian same-sex couples also meet guidelines for an earlier-than-expected wedding on home soil.

Tuazon-McCheyne has made his own contribution to Australia’s same-sex marriage debate, prompting a change to the Marriage Act in 2004 when he attempted to have his same-sex Canadian marriage recognised in the family court.

“I’ve been married for almost 18 years and finally my wedding is recognised,” he said. “The moment I marry Megan and Stephanie is going to extra special.”