Election 2016: Coalition plays down Labor fears same-sex marriage poll would be 'platform for homophobia'

The Turnbull government insists it has confidence in the Australian people to appropriately handle a plebiscite on same-sex marriage.

Opposition Leader Bill Shorten has labelled a possible national vote on gay marriage as a taxpayer-funded platform for homophobia.

But Finance Minister Mathias Cormann played down any potential community harm.

"The coalition does have confidence in the Australian people," he told reporters in Canberra on Monday.

Labor frontbencher Catherine King said the plebiscite should be canned.

"It will be a very divisive time in our nation and one we'll look back on, I think in some shame," she told ABC Radio.

Prime Minister Malcolm Turnbull said he expects parliament to swiftly legislate for a plebiscite if the coalition wins the July 2 election.

"I would hope that the plebiscite could be held before the end of the year," he told reporters in western Sydney.

Opposition Senate leader Penny Wong brushed aside questions over whether Labor would support legislation on the floor of parliament.

"No-one has seen the bill," she told reporters in Canberra.

Senator Wong said coalition MPs and senators, such as George Christensen and Cory Bernardi, had demonstrated an incapacity in the past to have a respectful debate on marriage equality.