Mayor de Blasio’s name was dragged into the bribery trial of ex-union official Norman Seabrook on Tuesday when a defense lawyer referred to Hizzoner’s relationship with the government’s star witness.

De Blasio donor-turned-felon Jona Rechnitz is scheduled take the stand as soon as Wednesday to tell the Manhattan federal jury that he plied Seabrook, the powerful former head of the Rikers guards’ union, with cash and gifts on behalf of a hedge-fund pal.

In exchange, Seabrook invested $20 million of the union’s hard-earned money in the pal’s now-defunct hedge fund.

Rechnitz is also expected to divulge — for the first time publicly — his efforts to bribe other city officials, including a fundraiser for de Blasio.

Rechnitz was so rich that “he spent more money on Knicks tickets than he paid on taxes,” defense lawyer Henry Mazurek said in opening statements.

And he was so connected that “he calls a fellow by the name of Bill de Blasio on his personal cell phone and gets an answer.’’

Rechnitz will be forced to answer questions about his efforts to buy City Hall officials as defense lawyers attempt to paint him as a serial crook who is lying about Seabrook and hedge-fund manager Murray Huberfeld in hopes of landing himself a lenient prison sentence.

Prosecutor Martin Bell admitted to jurors Tuesday that Rechnitz may have a lot of misdeeds under his belt.

But he is telling the truth about helping Huberfeld bribe Seabrook with $60,000 in cash stuffed in a black Ferragano man purse, Bell said.

“He came clean. He pleaded guilty,” Bell said of Rechnitz.