Allegra Spender says tax reform policy will be a cornerstone of her push in parliament if she is elected at the upcoming federal poll.
The independent candidate and businesswoman has called for a review into Australia's tax system ahead of the 2023 federal budget.
Ms Spender says Australia has a host of bad taxes, including payroll tax and stamp duty, and the corporate tax rate remains one of the highest in the world.
The Commonwealth government needs to prioritise supporting the states swapping stamp duty for land tax, she says.
"The level of waste and mismanagement of our taxes by this government has set a new low," she told the Union, University and Schools Club of Sydney on Friday.
"I've run businesses, and I know from personal experience the negative impacts on business of our inefficient and complex tax system."
Ms Spender - the daughter of the late fashion designer Carla Zampatti and the former Liberal MP John Spender - is running against Liberal MP Dave Sharma in the blue-ribbon seat of Wentworth in Sydney's east.
"This is a key issue for me and when it comes to putting my vote where it counts, I'll be looking very closely at what the major parties have to offer on the issue of taxation," she said.
"Our modern, increasingly digital economy must be underpinned by a transparent, competitive tax system."
Mr Sharma - a moderate Liberal - took back the seat of Wentworth for the party in 2019 after defeating independent Dr Kerryn Phelps.
But on a slim margin of 1.2 per cent, the seat is becoming a battleground ahead of the upcoming election, with the incumbent Liberal removing the party's branding and traditional blue hue from campaign material.
Ms Spender is trying to tap into disenchanted Liberals, targeting socially progressive but fiscally conservative voters angry at the government's climate policy and lack of action on a federal anti-corruption commission.
"I will push for strong climate policies, a federal integrity body, and crucially the establishment of a wide-ranging and thorough inquiry into taxation in Australia," she said during her speech.
The seat was held by former prime minister Malcolm Turnbull between 2004 and 2018 before he retired from politics after being rolled from the top job.
