Federal parliament is poised to legalise same-sex marriage at the final sittings for the year, but the MP citizenship issue could overshadow the historic change.
Senators' family history and citizenship details will be published on Monday, just two hours after lower house MPs return to work, having had their previous sitting week cancelled by the prime minister.
The same details for House of Representatives members are due on Tuesday night, and will be published on Wednesday.
It will then fall to senators and members to work out who, if anyone, is referred to the High Court to assess their eligibility for parliament under section 44 of the constitution.
Leader of the House Christopher Pyne said if there was "clear evidence" any MPs were citizens of another country when they nominated for election then the government would refer them on Thursday to the High Court "with or without Labor's concurrence".
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"It is important that the Australian people have confidence that everyone sitting in the parliament is entitled to be there under the Australian constitution," Mr Pyne told Sky News on Friday.
With the Senate having passed same-sex marriage legislation on Wednesday by 43 votes to 12, largely without amendment, the lower house is expected to endorse the bill.
However, Malcolm Turnbull has flagged his support for amendments to protect religious freedom.
Conservative Liberal backbencher Kevin Andrews said the amendments were "reasonable" and he expected strong support for them.
Liberal frontbencher Kelly O'Dwyer said she was "not persuaded" by the amendments, which will be the subject of a conscience vote.
If the bill is amended, it will return to the Senate for debate where Labor, the Greens and some crossbenchers are unlikely to accept the amendments.
With debate on the marriage bill set to start at 10am Monday and dominate the program for the whole week, the government has allowed for an extension of sitting time to deal with not only the draft laws but any outstanding citizenship issues.
The Senate, meanwhile, is expected to pass workplace laws repealing four-yearly reviews of modern awards.
However, less certain is the fate of a suite of draft laws which the government says will make housing more affordable, including setting up first home savers accounts through the superannuation system.
Two new senators, the Nick Xenophon Team's Rex Patrick and the Greens' Andrew Bartlett, will deliver their first speeches on Monday and Tuesday respectively.
On Thursday, Labor will seek the Senate's support to lower the threshold at which large private companies must disclose high-level tax information.
Pending the result of Saturday's New England by-election, Barnaby Joyce will attend the Nationals party room meeting on Monday.
However the government will be down his vote and that of another by-election contestant, John Alexander.
