Good morning, and I hope you're having a relaxing long weekend. I'm Thomas Morgan from the ABC's breaking news team. Good Friday will likely mean a more subdued mood on the federal campaign trail this weekend, but the major parties' housing spokespersons were far from it on last night's 7.30.

Plus, we have an unmissable story of how the stunning natural beauty of the Great Barrier Reef has reeled in people for centuries. And finally, Friday can only mean only one thing — our weekly quiz is back!

Welcome to Day 21 on the campaign trail. There were fiery clashes on last night's 7.30 between Housing Minister Clare O'Neil and her Coalition rival Michael Sukkar, at one point forcing a dramatic intervention by host Sarah Ferguson. You can watch the full debate here ▶️. Both major parties sense housing affordability is a key vote-swinger this election.

Plus: Bill Shorten and Christopher Pyne are back to give their verdict on how the leaders have performed during a busy third week of campaign.

Yes we Cairns? Queensland has long proved a thorn in Labor's side, but this morning we report on why the party is sensing a glimmer of hope in the state's far north. A split between the LNP incumbent and his anointed successor is just the beginning.

Trouble in the north: A public split has emerged between NT Senator Jacinta Nampijinpa Price and the Coalition's candidate for the NT electorate of Lingiari over a royal commission into child sexual abuse in Indigenous communities.

Analysis by Michelle Grattan: Peter Dutton this week unveiled the most radical proposal we've seen of this campaign — indexing personal income tax. The idea has merit, so why haven't we heard about it before?

'When you go underneath the water everything is so peaceful and calm': Today, ABC weather reporter Tyne Logan brings us the breathtaking natural beauty of the Great Barrier Reef — a place that has enchanted people for centuries. There, we meet people visiting the world's largest living structure, and find communities who not only rely on it for their livelihood, but see themselves as the "guardians" of its future.

Artificial intelligence: The emerging tech has prompted keen interest in how it can be adapted for treating mental health. As it turns out, nothing is new under the sun — chatbots have been used in psychotherapy since the mid-1950s. So can AI really replace a human therapist?

IVF bungle: A Brisbane woman has been mistakenly implanted with another woman's embryo, prompting a major response from Queensland Health . Sources have told the ABC there was little that could have been done to prevent the mix-up.

Superannuation: Over 1 million members of a major fund will be unable to access most services until June, in a move that has consumer groups "worried". It comes at a tumultuous time on global markets that could see nest eggs impacted.

• Trump administration: A looming long weekend has done nothing to slow down the frantic pace of US politics. Overnight, Donald Trump hit out at the US Federal Reserve Chair Jerome Powell for not lowering interest rates, saying his departure "cannot come soon enough". The Fed, like Australia's Reserve Bank, is supposed to be independent of government.
• Trade war: Meanwhile, Mr Trump has again indicated he's willing to back down on his 245 per cent tariffs on China , saying a "very good" trade deal can be done. Neighbours across the Asia-Pacific have been taking very different approaches in response to US import levies.
• China: Ukrainian President Volodymyr Zelenskyy has accused Beijing of supplying weapons to Russia's military. It comes as Timor Leste's president says he's interested in participating in Chinese military exercises, in a move that is sure to raise eyebrows in Canberra.

— Mavis Rofe, 86, loved her job as a lollypop lady at her local Bendigo school.

So when she was sacked over concerns about her physical ability, she took the fight all the way to Fair Work, and won. 

Keen readers of yesterday's AM newsletter will know which British city is suffering through a bin strike, so you can't get that one wrong. 

But how much do you know about this week's happenings? Test yourself with our weekly quiz!

That's it for now. Thanks for your company, and enjoy the rest of your weekend. I'll be back at the same time on Monday.

Thomas and the ABC News Digital team.

Clare O'Neil accuses Michael Sukkar of speaking "absolute garbage" on social housing as 7.30 host Sarah Ferguson delivers an iconic live television moment.