Wolf's move came six days before the deadline set by the Democratic-majority state Supreme Court to impose new boundaries for Pennsylvania's 18 congressional districts, routinely labeled as among the nation's most gerrymandered.
Wolf's office, which has not publicly released the governor's own proposal, said it remained possible that Wolf would submit one to the court. He also left open the possibility of working with the Legislature to submit a consensus map by Monday's deadline.
Republican lawmakers threatened a federal lawsuit and accused Wolf of lacking constructive ideas when he rejected their proposal. Some of his criticisms were "absurd," they said, and they challenged him to produce a fair map that can be put up for a vote.
Redrawing the map of Pennsylvania districts could boost Democrats nationally in their quest to take control of the U.S. House. Barely three months before May's primary election, district boundaries remain up in the air.
The governor said his office's analysis of the plan put forward Friday night by leaders of the GOP-controlled Legislature concluded that it was clearly designed to help Republican candidates.
"There is basically no chance it wasn't drawn in a way to benefit Republicans," said Wolf's press secretary, J.J. Abbott.
Abbott also countered that Wolf had given helpful criticism of the map, pointing to unnecessary splits in suburban Philadelphia's heavily populated Montgomery County and the Wilkes-Barre area and packing densely populated areas into small districts.
Moon Duchin, a Tufts University mathematician and who studies redistricting, reviewed the map for Wolf and called it "extremely, and unnecessarily, partisan" in a one-page summary released Tuesday.
An analysis conducted through PlanScore.org - created by political scientists, legal scholars and digital mapmakers - concluded that the GOP's redrawn map "is still seriously skewed in favor of Republican candidates and voters."
But Republicans insisted that drawing more competitive districts is not a constitutional directive and is prohibitively difficult because Democratic voters live much more tightly packed together.
Republicans said their proposal adhered to the court's line-drawing benchmarks, eliminating dozens of municipal and county divisions and creating more compact districts. It also kept nearly 70 percent of residents - and every congressman - in their old districts, although it shifted key Democratic challengers into new districts and Wolf criticized it as keeping "nearly 70 percent of residents in districts the court found unconstitutional."
The state Senate's Republican majority leader, Jake Corman, said that rejecting the GOP's proposal allows the governor and "his friends on the Supreme Court" to get what they wanted, which is to draw their own new map.
Corman also warned that the state Supreme Court will create a constitutional crisis if it imposes new district boundaries. The U.S. Constitution reserves boundary-drawing power for state lawmakers, Corman said, but there is no time under the court's deadlines for the Legislature to draw and pass a new map.
"The governor should have accepted it. The only reason he didn't is because he doesn't think it elects enough Democrats," Corman said. "As he's plainly said, there's too many Republican seats."
The map being replaced was drawn by Republicans who controlled the Legislature and governor's office after the 2010 census. They broke decades of precedent, producing contorted districts that split cities or shifted them into new districts to help maintain a big Republican advantage in Pennsylvania's congressional delegation.
They succeeded, securing 13 of 18 seats in three straight elections in an often-closely divided state where registered Democratic voters outnumber Republicans and Democrats hold a large majority of statewide offices.
Only Texas, California and Florida send more Republicans to the U.S. House.
The court struck down the district boundaries Jan. 22, siding with registered Democratic voters who sued last June. The boundaries "clearly, plainly and palpably" violated the state constitution, the justices wrote in a 5-2 decision that broke along partisan lines.
The court said Republicans put partisan interests above other line-drawing criteria, giving GOP candidates an unfair edge. Republicans counter that the court had no power to invalidate the congressional boundaries.
The U.S. Supreme Court earlier rejected a Republican appeal to halt the state court's order.
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