God, Queen and country will be the focus of the first sitting day of parliament for the year in Canberra.
MPs and senators will start the parliamentary year on their knees, with a church service featuring Bible readings by Prime Minister Scott Morrison and Labor leader Anthony Albanese.
The first order of business for the lower house will be a speech by Mr Morrison to mark the Queen's platinum jubilee, before the chamber debates controversial religious discrimination laws.
In the Senate, Victorian Liberal Greg Mirabella will be sworn in to replace Scott Ryan.
The government faces a slightly trickier time getting its bills through parliament, with Northern Territory senator Sam McMahon heading to the 15-strong Senate cross bench.
Senator McMahon has been dumped as the NT CLP's Senate candidate for the upcoming election and has some outstanding unaddressed complaints against the party.
The government was already having to contend with at least two coalition senators, Gerrard Rennick and Alex Antic, threatening to stymie legislation unless the government acts to end COVID-19 vaccination mandates.
Senator Rennick told Sky News there were questions to answer over serious adverse effects of vaccines on young people.
His concern comes despite global medical evidence showing the benefits of vaccination in terms of preventing serious illness and death from COVID-19 far outweigh any side-effects.
Treasurer Josh Frydenberg is expected to bring to parliament laws to enable tax deductibility for purchasing COVID tests for work purposes.
The Senate is scheduled to debate laws dealing with disability support, mitochondrial donation, corporate meetings, investment funds, federal family violence orders and changes to the pension loans scheme.
Labor will be seeking to talk up questions within the coalition about the prime minister's credibility, following the leaking of text messages describing him as a "liar", "hypocrite" and "complete psycho".
Nationals leader Barnaby Joyce, who sent one of the text messages, has since apologised and declared Mr Morrison to be a "trustworthy" person.
Mr Albanese said the government was too caught up in personality battles and not focusing on the things that mattered to Australians like solving the aged care crisis and dealing with the rising cost of living.
Mr Morrison and Mr Albanese attended a Last Post ceremony at the Australian War Memorial on Monday evening to mark the start of the parliamentary year.
