Welcome to Need to Know this Tuesday, May 19.

US President Donald Trump said he would delay an attack on Iran, originally planned for Tuesday, after being asked by leaders in Saudi Arabia, Qatar and the United Arab Emirates. He said that “serious negotiations” are now underway and that Gulf leaders are confident that an acceptable deal can be reached.

Treasurer Jim Chalmers says he wants to “dispel some of the myths” that have emerged around the budget, particularly around the changes to the capital gains tax discount for investors in both property and shares. He said that the government was happy to cop some political blowback from the changes.

Deep in the middle of a blockbuster legal battle with its former top radio hosts Kyle Sandilands and Jackie Henderson, ARN Media has made two new, high-profile talent signings: Today show cohost Karl Stefanovic and media personality Eddie McGuire.

The government will start legislating the controversial tax changes in the budget after parliament resumes next week, but the changes to trusts will not appear until later in the year.

Reserve Bank of Australia assistant governor Sarah Hunter said oil price shocks resulting from the war in Iran have exacerbated Australia’s already complicated inflation challenge.