Salim Mehajer has launched an urgent challenge to his suspension from Auburn Council, with a fast-tracked Supreme Court hearing set for Friday.

The hearing was expedited by Justice Peter Garling instead of granting the councillor a stay, which would have stopped the suspension taking effect pending the outcome of the appeal.

In a decision delivered last Friday, the NSW Civil and Administrative Tribunal blasted Cr Mehajer for his "hubris" and suspended him from council for four months for failing to disclose his financial interest in a property when voting on changes adding $1 million to its value.

The tribunal heard the 29-year-old deputy mayor of Auburn failed to disclose a family company's interest in a commercial building in Mary Street, Auburn, when the council voted to increase floor space ratios and building height in late 2012 and 2013.

But Cr Mehajer vowed to appeal his suspension "for the sake of my constituents".

His lawyers lodged the appeal on Tuesday and the Supreme Court set the matter down for an urgent hearing at 2pm on Friday.

The suspension from council is the latest in a string of legal dramas enveloping the controversial developer. Cr Mehajer's lawyers indicated in the Downing Centre Local Court on Tuesday that he will plead not guilty to allegations of electoral fraud in the 2012 council ballot.

He has described the charges as part of a "hidden agenda" to remove him from council.

The axe is already hanging over Auburn Council, which has been given notice by the state government to show cause why it should not be suspended ahead of a public inquiry led by Sydney silk Richard Beasley.

NSW Opposition Leader Luke Foley has previously said the "root of evil" was the Coalition government's law allowing local councillors to vote on their own development interests if they disclosed them.

"That was letting the kids into the candy shop," Mr Foley said. "Let's not pretend this is about one colourful character. He's just the personification of everything that's wrong with the system at the moment."

Local Government Minister Paul Toole has said the public inquiry into Auburn City Council is not affected by Cr Mehajer's suspension, nor is the 14-day period the council has to present why it should not suspended.