Mayor-elect Bill de Blasio continued his pre-inauguration appointment spree today with five more picks, including the man who will negotiate the next round of municipal labor contracts.

Robert Linn, whom de Blasio’s transition team describes as “a life-long negotiator of labor contracts and arbitrator of labor disputes,” will head the Office of Labor Relations. Among his chief tasks will be negotiating labor contracts for municipal unions that have gone without them for a while, in some cases for years, and are angling for retroactive pay raises that de Blasio has said he does not intend to offer without cost savings to even out the city’s balance sheet.

UFT President Michael Mulgrew responded to the appointment today by emphasizing the tough road ahead.

“We have a lot of work to do on the city’s labor contacts, and we look forward to professional negotiations based on integrity and respect,” Mulgrew said.