Two former federal treasury secretaries have united in a fresh call to abolish stamp duty in favour of a land tax from which most farming land and all existing home owners would be exempt.

Ken Henry and Martin Parkinson will appear at a conference on Monday at NSW Parliament to discuss federal and state finances, as part of a review being conducted by former Telstra CEO, David Thodey.

Former treasury secretary Ken Henry says that stamp duties create an unfair hurdle for young homeowners. Credit:Louie Douvis

Dr Henry says the stamp duties levied by state governments on property purchases create an unfair hurdle for young aspiring homeowners.

“It’s a big obstacle for first home buyers - saving for the deposit and then saving for the stamp duty - it’s just nuts," he said. "Particularly in Sydney, it’s a massive bill they’ve got to pay.”