Democrat Ronnie Musgrove and Republican Roger Wicker were close enough friends to share a Jackson apartment 15 years ago when they served together in the state Senate.

Now they’re in a highly competitive race for the U.S. Senate, and they’re rolling up their sleeves for a bare-knuckle political battle.

Within moments of announcing his candidacy on Monday, Musgrove started attacking Wicker’s congressional record. Musgrove said Wicker has voted to increase the national debt and to provide “billions of dollars in special interest pork” for states such as New York, California and Kansas. He also said Wicker has been weak on restricting illegal immigration.

“Roger Wicker will spend your tax dollars on a mule museum (in California) but he won’t spend the money for more border guards,” Musgrove said. “If that doesn’t say something about his priorities, then I don’t know what will.”

Wicker campaign spokesman Brad Ferguson responded that Wicker stands by his record.

“It is disappointing that Ronnie Musgrove waited until only his sixth or seventh breath to get down in the mud and start negative campaigning by criticizing Sen. Wicker,” Ferguson said. “This may be a new record for Mississippi campaigns.”

Musgrove, 51, served one term as Mississippi governor before losing to Republican Haley Barbour in 2003.

Wicker, 56, served 13 years in the U.S. House. Last week, Barbour appointed Wicker to temporarily fill the U.S. Senate seat left vacant by the Dec. 18 retirement of Republican Trent Lott. Wicker resigned his House post to take the Senate job.

The winner of a special election later this year will serve the rest of the six-year term that ends in January 2013.

It’s rare for Mississippi to have an open Senate seat because the state historically has sent incumbents back to Washington for decades. Lott retired with five years left in his third six-year term. He was first elected to the Senate in 1988 after serving 16 years in the House.

Wicker, of Tupelo, had developed seniority on the powerful House Appropriations Committee.

Musgrove said Monday that Wicker has voted against increasing the minimum wage and extending unemployment benefits for people whose jobs moved overseas.

“Me and Wicker are still good friends,” said Musgrove, who shared a Jackson apartment with Wicker for three legislative sessions in the early 1990s. “We just disagree on the issues.”

Wicker’s campaign spokesman took a jab at Musgrove’s 2003 loss to Barbour.

“The people of Mississippi are tired of politicians like Mr. Musgrove and their negative attacks, and I don’t think they are going to stand for his brand of politics,” Ferguson said. “They said so once, and they will say so again.”

Barbour set the special election for Nov. 4 — the same day as the regular general election. But Attorney General Jim Hood, who is a Democrat, said state law requires a special election to be held within 100 days of the time the Senate seat became vacant. Lott retired Dec. 18; a special election within 100 days would be in late March.

Hood has filed a complaint in Hinds County Circuit Court seeking to move up the election. A hearing on that complaint is set for early next week.

A longer election season could help Wicker because he would have more time to develop statewide name recognition as the incumbent.

Elton Barry of Crystal Springs was among about 40 Musgrove supporters who attended the campaign announcement at the War Memorial building in downtown Jackson.

“He’s just always been a man of principle, a lot of conservative Mississippi values,” said Barry, whom Musgrove appointed as assistant adjutant general of the Mississippi National Guard. Barry held the post from 2000-2004.

Musgrove said a Senate race will cost several million dollars. He said he is not allowed to move money from his state campaign finance account into the federal race.

Musgrove is an attorney in private practice in Madison County. He served two terms in the state Senate from Batesville from January 1988 to January 1996. He served one term as lieutenant governor from January 1996 to January 2000, and one term as governor from January 2000 to January 2004.

Wicker, who has a law degree, served seven years in the state Senate before being elected to Congress in 1994.

Former U.S. Rep. Ronnie Shows, a Democrat from Bassfield, also says he intends to run for the Senate. Shows was first elected to a southwest Mississippi congressional seat in 1998. Mississippi lost one of its five House seats after the 2000 Census and Shows’ district was combined with that of Republican Chip Pickering. Shows lost to Pickering in 2002.

Two high-profile Mississippi politicians — Pickering and Democratic former Attorney General Mike Moore — have said they will not run in the special election for the Senate.