Younger Australians struggling with cost-of-living pain will be given new freedom to earn more before they have to start repaying HECS debts, part of a Labor plan designed to shift the political debate back to the economy.

Dogged by revelations over the Qantas upgrades saga and his close ties to former chief executive Alan Joyce, Prime Minister Anthony Albanese will use a supporter rally in Adelaide on Sunday to promise lifting the Higher Education Contribution Scheme thresholds from $54,000 to $67,000 in 2025-26.