He and other undecided members particularly object to a targeted rate for transport which takes average household rates increases to 9.9 per cent.
Mr Watson also has reservations about a plan in the budget to sell $650 million of non-core assets over the next 10 years.
Other factors like new revaluations and completing the move to a single rating system for the Super City will see average increases of 15 per cent or more in many suburbs.
Poorer suburbs like Mt Roskill, Avondale, New Lynn, Mangere, Otahuhu, Beach Haven and Glenfield are among the hardest hit.
About 4000 households are facing 40 per cent-plus rates increases.
It is a total nonsense for Auckland councillors to abstain on the budget, said Auckland Chamber of Commerce chief executive Michael Barnett.
The business leader today said the budget was not fit for purpose and councillors should not abstain.
Councillors still thinking of abstaining are Cathy Casey, Ross Clow and Wayne Walker.
Another undecided councillor, Mike Lee, said he planned to vote on the budget after he hears and reads what is reported at Thursday's governing body meeting.
Senior officers have warned councillors about the consequences of not passing the budget.
Chief finance officer Sue Tindall said if the budget was not passed by June 30, rates could not be struck for the new financial year, beginning on July 1.
"This would give rise to a potential issue with respect to securing cashflow. Council would be obliged to notify bankers and other relevant financial agencies," she said.
Ms Tindall said the Office of the Auditor General had completed the audit process for the budget and councillors "would have no reason not to adopt the plan" after making budget decisions in May.
She did not say if councillors have the power to make last-minute changes to the budget.
How they'll vote
For(8)
Mayor Len Brown
Arthur Anae
Bill Cashmore
Linda Cooper
Chris Darby
Alf Filipaina
Calum Penrose
Penny Webster
Against(7)
Cameron Brewer
Chris Fletcher
Denise Krum
Sharon Stewart
George Wood
Dick Quax
John Watson
Abstain/uncertain(4)
Cathy Casey
Ross Clow
Mike Lee
Wayne Walker
Absent(2)
Penny Hulse
John Walker