Rep. Howard CobleJohn Howard CobleNC delegation pays tribute to late former Rep. Coble Former NC Rep. Howard Coble dead at 84 Lawmakers pay tribute to Howard Coble MORE (R-N.C.) announced he will retire at a Thursday press conference in his district.

Coble, who is 82 years old and North Carolina's longest-serving congressman, has had health problems in recent years and cited those as playing a part in his decision to retire.

"It's time for me to step aside," he said.

Coble's district is heavily Republican: Mitt Romney won 58 percent of the district's vote in 2012.

Two Republicans have already announced bids for Coble's seat this year: former GOP county chairman Nathan Tabor and Rev. Mark Walker.

The field is likely to grow. Phil Berger Jr., the son of North Carolina state Senate Majority Leader Phil Berger (R), is also said to be interested in the seat, and some Republicans have suggested Michael Steel, a North Carolina native who is House Speaker John Boehner's (R-Ohio) top spokesman, might be interested in a run.

This post was originally published at 9:00 a.m. and has been updated.