Environmental attorney Cory Briggs has sent a letter to Mayor Bob Filner asking him to resign.

Here is the letter he sent Tuesday.

I have spent the better part of my career standing up for principles of open, accountable, responsible government. It is clear to me that your office has violated those principles and that it would be impossible for you to successfully continue in the office without long-term damage to those principles and hte community’s efforts to see them fully implemented at City Hall.

We’ll have more as the story continues.

Briggs had already expressed concern about the way the increasingly controversial Sunroad donation played out. Here’s a simple explainer of the legal issues there.

Update 10:33 a.m.: Briggs is hardly a political foe to the mayor. He donated to the mayor’s campaign.

In a brief telephone conversation, Briggs would say only this: “I hope people handle this respectfully and don’t distort it into something political. It’s all about principle.”

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