This is chance for gay marriage: Senator

A failed plebiscite into gay marriage will spell the end of the matter at least in this term of parliament, a cabinet minister says.

""Yes, I expect it is," Simon Birmingham told ABC radio on Tuesday, when asked whether the failure of enabling legislation to realise the planned public vote on February 11 would mean it's dead.

"Really it falls back on Mr Shorten and the Labor party, the Greens and others who've advocated for this change ... to think long and hard whether they want to delay ... this issue for another few years at the least," he added.