Washington (CNN) The Supreme Court declined Monday a request from Pennsylvania Republicans to block a lower court ruling that ordered Pennsylvania to redraw congressional lines.

Justice Samuel Alito issued the order.

The ruling will have massive ramifications for the 2018 midterm elections, where Republicans' control of the US House is on the line and Democrats are targeting a handful of GOP-held seats in Pennsylvania.

Republicans had hoped the Supreme Court would keep the current maps -- where Republicans hold 12 of 18 seats in Pennsylvania and are expected to keep a 13th in a March special election -- in place through this year's elections.

The Pennsylvania Supreme Court, following a challenge from Democrats, enjoined the existing congressional districts in the 2018 primary and general elections holding that the Republican-drawn maps "clearly, plainly and palpably violates the Constitution of the Commonwealth of Pennsylvania." The court said the Pennsylvania General Assembly should submit a congressional redistricting plan later this week.

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