Oakland Mayor Ronald V. Dellums owes the residents of this great city an explanation.

And if he can't provide one, he owes his resignation.

The mayor is by no means the first public figure to run afoul of the Internal Revenue Service. The Internet is filled with stories of wealthy people and celebrities who have shirked their tax duties. But Dellums holds public office.

He is a hometown hero entrusted with the highest public office Oakland can offer. His $239,000 tax bill is peanuts compared with the weight of his responsibility as Oakland mayor.

Anyone can make an honest mistake, and if that's all this is, then no harm, no foul.

But Oakland residents deserve to know why the mayor was unable to handle his legal obligation to pay income taxes, because it's a reflection of his ability to handle responsibility, including the management of a city that has placed its trust, and a whole lot more, in his hands.

If Dellums can't come clean with the people who put him in office, the same people he promised would benefit from the transparent operations of the mayor's office, there is no reason left for residents to believe anything else he has to say.

Dellums' promised to guide our city of 400,000 with fiscal prudence and wisdom and the experience gained from 27 years in federal governance. He pledged to develop and push for public policy goals that benefit all citizens. Oakland residents entrusted their livelihoods, jobs, homes and the safety of their families to his leadership.

They are deserving of far more than a vague 16-word statement issued from behind the coattails of his press secretary.

Yet, Dellums was visibly agitated when reporters asked him about the tax trouble after a town hall meeting in West Oakland on Monday night shortly after the East Bay Express reported the story.

"We owe taxes, it's now being dealt with, and will be dealt with expeditiously. Period. P-E-R-I-O-D."

Had the mayor acted expeditiously, the matter would not have reached a point where the Internal Revenue Service issued an Oct. 14 order to place a lien on the mayor's real and personal property. It would have held no news value.

It's only after numerous opportunities to address serious situations that the IRS takes such drastic actions, Kristin Pace, an Oakland tax attorney, told The Chronicle. "He's pretty far down the path," she said.

IRS tax records show Dellums and his wife, Cynthia, did not pay their full tax bill in 2005, 2006 or 2007, his first year as mayor.

It's not as if there weren't warning signs of Dellums' preference to live beyond his financial means. The mayor made no bones about requiring amenities when he came into office. He asked the Oakland City Council for a $60,000 raise and received it. He required a driver and more than the standard security detail the Oakland Police Department provides every mayor. And Oakland taxpayers again provided the means and resources to make it happen.

The debt owed to this city by Dellums is incalculable and there is nothing but pride - or arrogance - standing between him and a full public disclosure of the facts surrounding his tax problem.

Anything short of that constitutes unacceptable behavior by a public official and violates the public contract between an elected official and the constituency the office serves. I tried to reach the mayor for comment - but he declined to speak with me, his press secretary Paul Rose told me.

No one has asked Dellums to disclose anything that any other politician in the same set of circumstances wouldn't be asked to explain.

If he cannot provide a public explanation for a controversy that has become another national embarrassment for this city, it's difficult to see how continuing in his current position is going to be good for anyone - either him or Oakland's citizens.