A longtime employee is set to put the lie to Bernard Madoff’s claim that he launched his epic Ponzi scheme during the recession of the early 1990s.

David Kugel, a former supervisory trader at Madoff’s investment firm, has been cooperating with authorities and plans to plead guilty in Manhattan federal court on Monday, prosecutors revealed yesterday.

In a letter to the judge, the feds said Kugel will admit conspiring in Madoff’s record $65 billion fraud “beginning in the early 1970s through December 2008.”

Kugel faces up to 85 years in prison.

Kugel made more than $8 million working for Madoff, and he and his family pocketed more than $13 million in phony profits after investing $25,000 with the fraudster in 1977, court papers show.