Former mayor Willie Brown has been sued by his political frenemy Joe O’Donoghue — and not for the first time.

In this most recent legal action, dated July 2, O’Donoghue — an on-again, off-again Brown ally and political donor — filed suit in San Francisco Superior Court, claiming Brown misused and wasted $50,000 intended to contribute to London Breed’s mayoral victory.

“I have no comment for you,” Brown told Mission Local on Saturday morning. When asked if the suit had any merit, he responded, “read the suit. Have your people talk about the suit. Stay with the suit. That’s all.”

O’Donoghue, however, had lots of comments: “I don’t know why Willie did what he did, but he did it to me — and he fucked with the wrong guy.”

The longtime former chieftain of the Residential Builders Association has a lengthy — and complex — relationship with Brown. O’Donoghue and the RBA were major movers and shakers in propeling Brown into City Hall Room 200 more than two decades ago, and subsequently benefited from the live-work loft construction boom that transformed SoMa. In more recent years, O’Donoghue stepped down as head of the RBA and largely faded from the city’s political scene. He sued Brown, now a city influence peddler and Chronicle columnist, in 2015 over an Oakland condo tower real estate deal gone sideways, but the two settled one year later with a jovial, back-slapping display.

But now the mood has changed once more. “I’m never fucking doing business with Willie Brown again,” O’Donoghue swears.

The entirety of his legal case at this point can be summed up in one paragraph:

The essential terms of the agreement are as follows: O’DONOGHUE would give out a check for $50,000 to BROWN made out to BROWN’S designee and the money would be held in trust until an independent organization could be set up supporting London Breed for mayor. At that point, the money would be donated to that organization, and the money would be used exclusively as an independent expenditure in support of London Breed. BROWN gave the money to a charity he favors, which claims to have used the money for voter turn out efforts. That was in no way the agreed use of the money which was as stated above.

While not listed in the complaint, O’Donoghue told Mission Local the “charity” that received the $50,000 is the A. Philip Randolph Institute.

“I wanted London to win by a large margin. We’re looking at the next race; we wanted to eliminate competition” in 2019, O’Donoghue explains. “But London’s win was very narrow.” He blames Brown for not “spending my money where it should have been spent.”

O’Donoghue notes he has, in the past, put massive amounts of political dollars where Brown told him to, no questions asked, and never before felt burned. These would include five- or six-figure gives to Gov. Gray Davis and, then, his usurper Gov. Arnold Schwarzenegger. This wasn’t ideologically consistent, but that wasn’t the point. The point was to gain sway. “What he got is access. That’s more important than a cut,” O’Donoghue told me in 2016. “Willie never benefits financially from donations. That I can say emphatically.”

But now he’s not so sure. O’Donoghue writes off vote registration efforts as an exceedingly poor use of his $50,000 — and one that’s challenging to verify.

“It’s bullshit. It’s a joke: I’d have never given money for registration. If I wanted to do registration, I’d have done that myself. No one knows more about registration of voters than I do — we elected Willie Brown to office. He didn’t know jack shit about grass-roots organizing. He didn’t know the name of one precinct captain,” O’Donoghue said. “And if you want to hide money, you do it through registration. How do you show expenditures for registration? My money didn’t necessarily go to that registration. They will never be able to show that.”

O’Donoghue claims Brown specifically contravened his wishes on how the money would be spent — the cause of the complaint is “breach of contract” — and that this alleged shenanigan has cost London Breed hundreds of thousands of dollars in future contributions. With the mayor-elect, who is to be sworn in on July 11, facing re-election in November 2019, O’Donoghue characterizes this $50,000 as an intended down-payment. He’d planned on going around to “wealthy Irishmen” and raising perhaps six times that amount for the next election. But not anymore.

“We will never get that $50,000 back,” laments O’Donoghue. “But the principle is to show how Willie Brown does business. Any future dealings anyone has with him, buyer beware.”