Updated at 3:41 p.m. with information about pledged lawsuit from Republicans.
The Illinois Republican congressional delegation is deriding Gov. Pat Quinn's decision to approve a new map for U.S. House districts.
The 10 GOP congressmen Illinois Republican congressional delegation in the pledged a lawsuit in a statement Friday over what they say is a "highly partisan map that tears apart communities."
The map hastily approved by lawmakers during a holiday weekend last month lumps five GOP representatives into districts that force them to run against other incumbents in 2012.
The congressmen say Quinn's action "disrespects the will" of voters who elected a majority Republican House last fall.
Original Stories with 1:43 p.m. addition of Republican response.
Illinois Gov. Pat Quinn has approved new congressional-district lines that will send 18 people to Capitol Hill - one fewer than the past decade.
Quinn signed legislation Friday that OKs a map for a pared-down congressional delegation.
There will be fewer Illinoisans in the U.S. House in 2013 because of nationwide population shifts.
Critics - particularly Republicans - have thrashed the Democratic proposal because it creates just one district where Latinos represent the majority. The state's Latino population has grown 32.5 percent.
Quinn, however, says the congressional district map he's signed into law is fair and protects minority voters' rights. He says taxpayers had input at public hearings on both state legislative and congressional maps, even though the final product for the U.S. House was voted on less than 24 hours after it was publicized.
GOP lawmakers predicted a lawsuit over the lines as the General Assembly rushed to approve them before its May 31 spring adjournment.
Illinois Republican Party Chairman Pat Brady says the new congressional district lines the governor has approved is an attempt to "silence" voters.
Brady says voters sent a GOP majority to Congress just last fall. He says the map signed into law Friday by Democratic Gov. Pat Quinn is unfair to Republicans.
It lumps five GOP incumbents into districts where they'd have to run against other incumbents in 2012.
Brady says Quinn "lost all claims to the label 'reformer"' by approving the map and says he hopes courts will overturn it.
He says the map was released on a Friday and approved on a holiday weekend to avoid public scrutiny.
The proposal appeared for approval less than 24 hours after it was made public, despite Democrats' promises that it would get plenty of public scrutiny.