Rep. Martin Sabo, D-Minn., plans to announce Saturday he will not seek re-election, congressional staffers say.

Sabo, 68, has served in the House since 1979. He will make the announcement at a news conference in his home district of Minneapolis. Sabo is second in seniority to only fellow Democrat Jim Oberstar in the Minnesota congressional delegation.

Two Minnesota congressional staffers told The Associated Press of Sabo's plans to retire. Both requested anonymity because they didn't want to upstage Sabo's announcement.

Sabo's spokeswoman declined to comment Friday; Sabo's office issued a news release saying he would make a "major announcement" at his congressional office at noon on Saturday.

"He's been a steady force for progressive politics in the state of Minnesota," said Senate DFL candidate Amy Klobuchar, the Hennepin County attorney. "He has this quiet effectiveness, where he gets things done without a lot of fanfare. He's worked incredibly effectively for the people he's served."

The district is considered reliably Democratic. Sabo got 70 percent of the vote in 2004, and Democrat John Kerry won 71 percent of the district's votes in the presidential election that year.

Sabo's announcement is expected to set off a rush for the seat among DFL politicians in the state's safest district for Democrats.

"No matter what Congressman Sabo announces, we are 100 percent confident that Minnesotans will send a Democrat to represent them in Congress this November," said Bill Burton, a spokesman for the Democratic Congressional Campaign Committee.

The National Republican Congressional Committee didn't exactly play up its chances of winning the seat.

"Minneapolis is more Republican than it used to be, but it's not fertile Republican territory just yet," said NRCC spokesman Jonathan Collegio. "I would imagine that the party will find somebody to run on the ballot. It could end up being a fun, spirited campaign."

Potential DFL candidates include Mike Erlandson, Sabo's chief of staff and the former head of the DFL Party; state Sen. Scott Dibble; Hennepin County Commissioner Gail Dorfman; state Rep. Keith Ellison; and Minneapolis City Council member Lisa Goodman, said Blois Olson, the Democratic co-publisher of the Politics in Minnesota newsletter.

"These seats — they only come up once every 30 or so years, so that makes it a real opportunity," Olson said. "Because it's a safe seat, it allows whoever is elected to take leadership on significant issues of national importance — wherever the passions lie."

Dibble said he's strongly considering whether to run and will make a decision within a few days. Reached by cell phone in upstate New York, Dorfman said she would consider running.

The decision-making process will have to be quick, because DFL delegates will endorse a candidate for the seat on May 6 — leaving candidates just seven weeks to campaign for the party's backing.

Other possible entries on the list: Sabo's daughter, former state Sen. Julie Sabo; former Minneapolis Mayor Sharon Sayles Belton; R.T. Rybak, the current mayor; Hennepin County Commissioner Peter McLaughlin, who unsuccessfully challenged Rybak last November; Minneapolis City Council members Scott Benson and Gary Schiff; and state Rep. Margaret Anderson Kelliher.

Sabo, who chaired the Budget Committee in the early 1990s, currently serves on the House Appropriations Committee, where he has helped steer millions of dollars to the Twin Cities. He is also the ranking Democrat on the Appropriations Committee's homeland security subcommittee.

Sabo was born in North Dakota and was first elected to the Minnesota House at the age of 22. He quickly ascended to minority leader and then speaker.

Sabo's political rise was belied by a shy personality, which became even more of a rarity once he got to Congress. He was known for his passion for baseball, managing the Democrats' team in the annual congressional baseball game.

As Budget Committee chairman, he helped pass President Clinton's first budget.

Sabo defined himself as a "liberal decentrist," saying that he supported liberal issues but favored local control to federal control. He has been a harsh critic of President Bush's tax cuts, and has highlighted what he considers to be excessive CEO pay.

Sabo also carved out a strong role on transportation issues, and pushed for greater safety inspections of Mexican trucks entering the United States.