SACRAMENTO (CBS13/AP) – California Gov. Gavin Newsom apologized for what he called “a bad mistake” for not practicing what he’s been preaching in attending a birthday party for a longtime adviser.

Newsom has suffered harsh criticism since it surfaced Friday that he and his wife attended the party Nov. 6 with a dozen friends at the pricey French Laundry restaurant in wine country north of San Francisco.

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At his press conference addressing coronavirus on Monday, Newsom owned up to dinner.

The governor said he realized as soon as he sat down at the outdoor table that the group was larger than he had expected to celebrate the 50th birthday of Jason Kinney, a political adviser that Newsom said he has known for 20 years.

“I made a bad mistake,” Newsom said. “I should have stood up and … drove back to my house.

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“The spirit of what I’m preaching all the time was contradicted,” he added. “I need to preach and practice, not just preach.”

The lapse came just as California is seeing a surge in coronavirus infections and hospitalizations, and as health officials lobby residents to skip traditional Thanksgiving and holiday gatherings or self-quarantine if they travel.

More from CBS Sacramento:

State and local officials have largely blamed recent increases on such social gatherings, and media experts said Newsom’s failure to abide by his own rules may have hurt his credibility just as the state is trying once again to tighten them. Newsom announced Monday that more counties will move more quickly into increased business restrictions as the state tries to head off a further spike in cases.

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Copyright 2020 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.