NEW YORK — Brad Lander’s mayoral campaign missed a critical deadline to receive several million dollars in public matching funds next week for his mayoral bid.

It’s a surprising and embarrassing error for the city’s chief financial officer — a rule-oriented policy wonk who has thus far proven to be Mayor Eric Adams’ most formidable challenger.

His campaign acknowledged the missed paperwork but waved away any suspicion that the mishap reflects a hesitation in taking on Adams and a band of fellow lefty Democrats in next June’s primary. In fact, Lander will soon announce Alison Hirsh as campaign manager. Hirsh is chief strategy officer in the comptroller’s office, and will be leaving her government job Dec. 31.

A former labor union operative, Hirsh worked in City Hall under Bill de Blasio and was a senior adviser to Maya Wiley’s mayoral campaign in 2021.

Political insiders and Adams’ challengers are awaiting word from the New York City Campaign Finance Board on whether to grant Adams matching funds, given his federal indictment that alleges a straw donor scheme.

But it turns out it’s one of his leading opponents sharing — or stealing — that unenviable spotlight.

Lander, who has outraised every Adams challenger with nearly $1 million so far, will not get the 8-to-1 match on donations up to $250 when the board announces its determinations on Monday.

Campaigns must submit a “Certified Statement of Need” to qualify for public funds. Lander’s team missed the Nov. 22 deadline, according to a letter from CFB Senior Associate Counsel Mark Griffin the Lander campaign shared with POLITICO.

That’s an unfortunate — but recoverable — twist for the city’s chief financial officer. Lander will be eligible for the matching funds payment at the board’s Jan. 15 meeting, at which point he expects to be approved for as much as $3.5 million, according to a campaign official.

“We’re thrilled to build on our fundraising lead by receiving matching funds in the next few weeks as the race begins to take off,” Rebecca Rodriguez, Lander’s senior adviser, said in a statement.

Opposing camps have been speculating that the Brooklyn Democrat would defer his matching fund payment to keep open the option to run for reelection as comptroller with public money instead. But Lander has not shown any signs of wavering on running for mayor against a weakened Adams.

Adams’ campaign attorney Vito Pitta declined to comment on Lander’s situation, and said the CFB has acknowledged the timely receipt of the Adams campaign’s own statement of need.

The board is expected to announce Adams’ eligibility for public funds on Monday. CFB Board Chair Frederick Schaffer said in September that the board will “review all relevant information, including but not limited to the indictment, in order to uphold our city’s campaign finance rules and protect taxpayer dollars.”

After saying he was done seeking campaign contributions because he had hit his target, Adams resumed campaign fundraising on a trip to Puerto Rico this week, POLITICO first reported — apparently anticipating he may not receive matching funds.

Former City Comptroller Scott Stringer has hit the threshold to qualify for matching funds, and stands to be the only mayoral candidate to receive them Monday.

Stringer’s campaign and the CFB both declined to comment.

All other mayoral candidates did not raise $250,000 in matchable claims from at least 1,000 donors before the Oct. 11 deadline.