HARRISBURG, Pa. — Republican U.S. Rep. Charlie Dent of Pennsylvania, a leader of an influential caucus of GOP moderates and a critic of President Donald Trump, said Tuesday that he will resign from Congress in May, after announcing last year he would not seek re-election.

Dent's announcement sets up the potential for a special election as early as mid-summer to serve the remaining months in his term while candidates campaign for a full two-year term in the November election.

It would be the second special election in Pennsylvania this year, following Democrat Conor Lamb's victory last month in a southwestern Pennsylvania district long held by Republicans.

The seven-term Dent did not give a precise departure date in Tuesday's statement. He said he made the decision after discussing it with his family and careful reflection. Dent is pursuing numerous job opportunities but had no definitive plans as of Tuesday, his spokesman said.

Dent has been a frequent critic of Trump and polarization, ideological rigidity and dysfunction on Capitol Hill. Gov. Tom Wolf will have 10 days from Dent's resignation date to set a special election. The date of the special election must be at least 60 days from the time the governor schedules it.

Major-party candidates for the special election are nominated under party rules. The district, as currently drawn, has slightly more registered Democrats than Republicans, but Trump won it by more than 7 percentage points over Democrat Hillary Clinton in 2016's presidential election.

Pennsylvania's Republican Party chairman, Val DiGiorgio, called Dent "a strong public servant" and said the party would work to ensure the seat stays in Republican hands.

The boundaries of Pennsylvania's congressional districts were redrawn earlier this year under court order in a gerrymandering case, and the newly drawn district around Dent's Allentown-area home base is considered a toss-up in November's election. Republicans and Democrats are headed for contested primaries May 15 in the seat.

Wolf, a Democrat, thanked Dent for his service.

"Charlie Dent is a voice of reason and civility that breaks through the chaos and partisanship of Washington and he will be missed," Wolf said in a statement.