House Speaker Nancy Pelosi does not support the effort by her fellow Democratic congressional leaders to expand the Supreme Court from nine justices to 13 — and will not bring such a bill to the floor for a vote, she said Thursday.

Pelosi made the revelation while during her weekly press conference, offering a stark “No” after being asked about the measure being introduced to expand the nation’s highest bench.

“I support the president’s commission to study a such a proposal,” she continued, going on to say that she and her members were focused on President Biden’s infrastructure package and not the federal judiciary.

As for whether she would eventually support packing the court, Pelosi said the jury was still out on the matter. “I don’t know that that’s a good idea or bad idea. I think it’s an idea that to be considered. And I think the president’s taking the right approach to, to have a commission to study such a thing,” the top-ranking House Democrat said, calling Biden’s move itself “a big step.”

“It’s not out of the question, it has been done before,” she went on to say, noting that “the history of our country a long time ago, and the growth of our country, the size of our country, the growth of our challenges in terms of the economy, etc. might necessitate such a thing.”

As for now, however, Pelosi is only backing the commission.

“I have no plans to bring it to the floor,” she said.

Asked about the proposal Thursday on Capitol Hill, Senate Majority Whip Dick Durbin (D-Ill.) offered similar sentiments to Pelosi.

“I’m not ready to sign on yet,” the No. 2 Senate Democrat told reporters, “I think this commission of Biden is the right move.

“Let’s think this through carefully. This is historic.”

House Judiciary Committee Chairman Jerrold Nadler (D-NY), along with Reps. Hank Johnson (D-Ga.) and Mondaire Jones (D-NY) and Sen. Ed Markey (D-Mass.), formally unveiled their legislation in a press conference outside the Supreme Court on Thursday, and will introduce it in the House in the afternoon.

Rep. Tom Suozzi (D-NY) slammed the legislation when reached by The Post after it was introduced, saying, “This is a system that has worked well for a long time. Changing it based on party control is not a good practice.”

During the 2020 Democratic presidential primary, Biden said multiple times he did not support packing the court, vowing in an interview with Iowa Starting Line that Democrats would “live to rue that day.”