Opposition leader Bill Shorten says Australia should "get on with it" after same-sex marriage was legalised in Germany.
The German parliament on Friday supported the move following an about-face by Chancellor Angela Merkel, who freed members to vote on their conscience rather than follow party lines.
"No expensive, divisive opinion poll - just a parliament doing its job. Well done Germany. Let's get on with it in Australia," Mr Shorten tweeted on Friday.
Fellow Labor MP Andrew Giles said it's shameful the Turnbull government won't allow politicians a free vote.
"Wonderful news for Germans. Shameful our PM won't let us vote for #equalmarriage #LoveIsLove," he tweeted.
NSW Independent MP and Australian Marriage Equality co-chair Alex Greenwich said the German government has demonstrated the issue doesn't need to be lost in politics.
"Marriage equality in Germany is a reminder that marriage equality in Australia takes from no one but will make a profound difference to the status and dignity of so many gay and lesbian Australians," he said in a statement.
"As Prime Minister Turnbull travels through Germany over the next week we ask him to observe the happiness this reform has brought to gay and lesbian people and their families across Germany and how the sky hasn't fallen in."
Debate was reignited in Australia this week after cabinet minister Christopher Pyne told a federal Liberal council function the issue of same-sex marriage could be resolved sooner than everyone thought.
But Mr Turnbull says his government remains committed to holding a plebiscite before MPs vote on the law change.