Glenn F. Ivey, until recently the top prosecutor for Prince George’s County, is preparing to announce his candidacy for the congressional seat held by Rep. Donna F. Edwards (D-Md.).

Ivey, 50, now a lawyer in private practice, has been calling prospective supporters and financial backers, and has already hired his former spokesman, Ramon Korionoff. Ivey declined to discuss his plans, but Korionoff confirmed them Tuesday.

“He is moving full speed ahead and laying the foundation to run for the House of Representatives,” Korionoff said in an e-mail.

Ivey’s decision to enter the race comes as Anne Arundel County Council member G. James Benoit (D) said Tuesday that he would explore his own candidacy. The redrawn district includes part of Anne Arundel and eliminates a part of Montgomery County, where Edwards, who is African American, has substantial political support among its growing minority population and among white liberals.

Ivey, who is African American, has twice run successfully countywide for state’s attorney in Prince George’s, which forms the core of the new district.

Benoit, 40, an Army veteran who is white, has served on the Anne Arundel council since 2006. He said in a statement that he is considering a run because Congress is busy “posturing” instead of focusing on “putting Americans back to work.”

The new congressional district was part of a package approved last week by the General Assembly. It was designed by Maryland Democrats in part to squeeze out Rep. Roscoe G. Bartlett (R) and extend the Baltimore district of Rep. John Sarbanes (D) toward the voter-rich Washington suburbs as he mulls a race for the U.S. Senate. The plan has come under fire from Republicans and from some African Americans and Hispanics.

Edwards, 53, declined to comment. She is not closely aligned with party leaders such as state Senate President Thomas V. Mike Miller Jr. (D-Calvert), who played a key role in redistricting.

“It is clear that there have been conversations going on for quite a while about who is to run against Donna. It is no secret that others have been approached as well,” said Montgomery County Council President Valerie Ervin (D-Silver Spring).

Del. Aisha N. Braveboy (D-Prince George’s), who is first vice chairman of the Legislative Black Caucus of Maryland, said Edwards “has been a wonderful representative for Congressional District 4, and has been acknowledged by the congressional leadership for her intellect, her understanding of the issues and her ability to work with her colleagues.”

Staff writer Ben Pershing contributed to this report.