Republican Pa. congressman won't seek reelection: report

Pennsylvania Republican Rep. Ryan CostelloRyan Anthony CostellloPennsylvania's Democratic lt. governor files to run for Senate Bottom Line Trump struggles to stay on script, frustrating GOP again MORE will not seek reelection to his district in 2018 as he faces a difficult midterm race in a district with a growing Democratic voter base, City & State Pennsylvania reported Saturday.

Despite having filed this week to run in the GOP primary for the state's 6th District in May, Costello told state and local Republican officials that he plans to drop out in the weeks before then, unidentified sources told the news outlet.

Costello reportedly met with former 6th District Rep. Jim GerlachJames (Jim) GerlachThe business case for employer to employee engagement 2018 midterms: The blue wave or a red dawn? Pa. GOP 'disappointed' by rep retiring after filing deadline MORE (R) and the state GOP chairman about the decision Friday, which he said would avoid a costly defeat for the party in the coming months. 

The Pennsylvania Republican has been rumored to be considering retirement from the Philadelphia-suburban area hit hard by a recent redrawing of the state's congressional districts. 

The redraw, forced by the state Supreme Court after determining the old congressional map was unconstitutional, raised doubts as to whether Costello could hold on in the competitive swing counties surrounding Philadelphia.

The district went from being one that Democratic presidential candidate Hillary ClintonHillary Diane Rodham ClintonGraham: Trump can make GOP bigger, stronger, or he 'could destroy it' Hillicon Valley: China implicated in Microsoft breach | White House adds Big Tech critic | QAnon unfazed after false prediction Jill Biden redefines role of first lady MORE won by just 1 point in 2016 to one she would have won by 9 points, ABC News reported.

Costello's move also comes after the GOP narrowly lost a special election in the Pittsburgh suburbs' 18th District, one seen as a barometer of Republican favor in the months before the midterm elections this fall.

Democrats hope to net at least 24 seats to regain control of the House.

Updated: 4:20 p.m.