A Mayor de Blasio donor and alleged cop briber is demanding that charges against him be dismissed over an evidence blunder that forced his corruption trial to be pushed back by five whole months.

Jeremy Reichberg, who’s accused of bribing cops Michael Harrington and James Grant, says the feds deprived him of his constitutional right to a speedy trial when they turned over a slew of new evidence on the eve of opening arguments, including 4,000 new wiretap recordings and hundreds of hours of new witness testimony — forcing the judge to postpone proceedings to Oct. 4.

“After living under the cloud of criminal charges for nearly two years, Mr. Reichberg looked forward to confronting the government’s accusations in May,” his lawyer, Susan Necheles, said in court documents. “It is solely because of the government’s failure to perform its duties with diligence that he has not yet had his day in court.”

Necheles asked the judge to sanction prosecutors for the delay.

The request comes the same week Reichberg’s alleged co-conspirator, Jona Rechnitz, took the stand in the retrial of ex-city jails union boss Norman Seabrook, saying that he and Reichberg bribed or attempted to bribe upwards of a dozen cops when Reichberg was a police liaison for the resident of Borough Park, Brooklyn.