BURLINGAME — After serving 20 years on the City Council, Rosalie O'Mahony can expect a pretty lengthy farewell tribute Monday.

The City Council will formally honor O'Mahony — a five-time mayor who lost a Nov. 3 bid for re-election to the council — with a proclamation at the beginning of that night's council meeting.

Mayor Ann Keighran said city officials want to ensure to honor O'Mahony before Dec. 7, when the council will change mayors and swear in Councilman-elect Michael Brownrigg.

"I think since she's put in 20 years of service there may be quite a few people there, so we figured we'd keep it kind of her night," Keighran said.

O'Mahony will be joined by Assemblyman Jerry Hill, D-San Mateo, San Mateo County Supervisor Mark Church and likely a representative over the phone from the office of U.S. Rep. Jackie Speier, D-Hillsborough, Keighran said.

"The city of Burlingame has been quite fortunate to have Councilmember O'Mahony on the council for 20 years," Keighran said. "She's given 20 years of selfless commitment and those are very far and few between."

O'Mahony was defeated Nov. 3 in a four-person field for three council spots, falling 92 votes short of Vice Mayor Cathy Baylock for the final seat.

The meeting will start at 7 p.m. at City Hall on 501 Primrose Road.

Mike Rosenberg covers San Mateo, Burlingame, Belmont and transportation issues. Reach him at 650-348-4324.