The Senate and its denizens will occupy the government in the coming week of federal parliament.
Legal action against two senators is set to dominate politics and the fallout complicates crossbench equations on key pieces of legislation.
Family First senator Bob Day has resigned to deal with his construction company collapse, and the government has revealed legal advice casting a cloud over both his and One Nation senator Rod Culleton's election.
The Senate will on Monday decide whether to refer Mr Day and Senator Culleton to the High Court, sitting as the Court of Disputed Returns.
The cloud hanging over the two crossbench spots changes dynamics as the government pushes ahead with its same-sex marriage plebiscite legislation and delays a pair of industrial relations bills.
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The government insists it doesn't know what will happen to the plebiscite bill, even though the numbers appear set against it.
"When you're in politics, lots of people make predictions," Liberal MP Tim Wilson told ABC TV on Sunday.
"But until the final vote is counted ... in the Senate you can't make any prediction."
Conversely, it has pulled legislation to re-establish the Australian Building and Construction Commission and a registered organisations watchdog - the bills used to trigger the double dissolution election - because it doesn't believe the Senate support is there yet.
Mr Wilson said it was doubtful those bills would go to the Senate before the end of the year.
Opposition leader Bill Shorten said the prime minister had spruiked the industrial relations legislation and a company tax cut as the two big reasons to vote Liberal at the federal election.
"Why did we have a double-dissolution election?" he asked on Sunday.
The "backpacker tax" bill is also before the Senate and Labor is open to a proposal from Tasmanian independent Jacqui Lambie to to drop the tax rate further to 10.5 per cent.
The government is set to introduce legislation for a lifetime Australian visa ban on asylum seekers on offshore immigration centres.
Labor is scrutinising the draft bill and will decide its position in a caucus meeting on Tuesday.
Indonesian president Joko Widodo had been due to address parliament on Monday morning but cancelled his visit to deal after a protest in Jakarta spiralled into violence.
