HARRISBURG — The chief justice of the Pennsylvania Supreme Court said Thursday that he is "very concerned" about an effort to impeach his four colleagues who voted to overturn the state's congressional district map and impose a new one.

"Threats of impeachment directed against Justices because of their decision in a particular case are an attack upon an independent judiciary, which is an essential component of our constitutional plan of government," Chief Justice Thomas Saylor said in a statement.

Saylor, elected to the court as a Republican, dissented from the majority in the case.

The impeachment effort faces resistance from at least one other key Republican — House Majority Leader Dave Reed, who controls the chamber's voting calendar. Impeachment proceedings must begin in the state House.

Reed, of Indiana County, said in a statement Thursday, "While I believe the State Supreme Court's decision to draw and implement their own congressional redistricting map is wrong, disagreement over the outcome of any particular case should not be grounds for impeachment."

State Rep. Cris Dush (R. Jefferson) introduced Tuesday four resolutions seeking to impeach Justices Christine Donohue, Kevin Dougherty, Debra Todd and David Wecht, who ran as Democrats. The four overturned the prior congressional map on the grounds it was a partisan gerrymander designed to favor Republicans and imposed a new one in time for the upcoming May 15 primary.

Dush spared Justice Max Baer, a Democrat who agreed the old map was unconstitutional but disagreed with the process for imposing a new one, and Justices Saylor and Sallie Updyke Mundy, a fellow Republican who also dissented from the court's order.