Jerry Jennings, the Democratic mayor of Albany, N.Y., opened his weekly radio show Friday with a joke: “Hello, this is Congressman Jennings — I mean Mayor Jennings.”

The mayor was making a less than subtle reference to news that Rep. Mike McNulty (D-N.Y.) will not seek an 11th term in 2008. Jennings is one of several Democrats mentioned as a possible successor to McNulty, and on his radio program he refused to rule out the possibility of running.

The jockeying among Democrats to replace McNulty in the 21st district is expected to be intense.

“The problem with Albany is, the field is going to get ugly,” said a Democratic consultant based in the state capital. “It’s huge. It’s going to be interesting to watch the intrigue.”

McNulty has a news conference scheduled for noon today at the Crowne Plaza Hotel in downtown Albany, and he is expected to announce his retirement plans then.

Officially, McNulty’s office wasn’t commenting Friday. But several sources on Capitol Hill and in New York said the 60-year-old Congressman has been calling colleagues and local political leaders, telling them that he has decided to leave Congress primarily for health reasons. He contracted polio at age 2 and now suffers from post-polio syndrome, which limits his mobility.

The timing of McNulty’s expected announcement, just eight days before voters in several municipalities in the Albany area go to the polls, puzzled political professionals in the capital because it requires some potential candidates to openly discuss the Congressional vacancy while they’re seeking re-election to their present offices.

McNulty was a reserved figure in Washington, D.C., who eschewed the spotlight. But back home he was a political powerhouse, a scion of a prominent Albany-area political family who was heralded for his ability to bring home the bacon and promote the interests of his district. McNulty’s family has held various local political offices for almost a century, and the Congressman has been winning elections since he was 22.

McNulty arrived in Washington after his predecessor, then-Rep. Sam Stratton (D-N.Y.), abruptly announced his retirement plans in 1988 just a few days after the candidate filing deadline. Local Democratic leaders tapped McNulty, who was then serving in the state Assembly, as Stratton’s ballot replacement, and he was elected easily.

Although the Albany Democratic machine remains one of the most potent in New York, party bosses are not expected to anoint a Congressional nominee this time.

“Back in the day, this would have been done with cigars and a poker game,” the Albany-based consultant said.

Still, there appeared to be a pecking order Friday among McNulty’s would-be successors, most of whom are Democrats.

At the top of the list were Jennings, the pugnacious four-term Albany mayor; Schenectady Mayor Brian Stratton (D), the son of the late Congressman; state Assembly Majority Leader Leader Ron Canestrari (D); and state Sen. Neil Breslin (D), who like McNulty and Stratton comes from a well-known local political family.

One of Breslin’s brothers is the Albany County executive, and another is a judge, and the Senator is close to Gov. Eliot Spitzer (D), which could prove beneficial in a crowded Democratic primary. Jennings and the Breslin family have been at odds for years.

Some New York observers expressed doubt Friday that Canestrari or Jennings would run. Canestrari is 64 and just became Majority Leader at the beginning of the year. Jennings is 59 and may not enjoy being one of 435 House Members after running the capital city for so long.

The list of other potential Democratic candidates includes Tracey Brooks, who runs the Albany office of Sen. Hillary Rodham Clinton (D-N.Y.); Albany Common Council President Shawn Morris; Schenectady County Legislature President Susan Savage; Albany County District Attorney David Soares; and former state Assemblyman Paul Tonko, who is chairman of the state Energy Research and Development Authority.

Brooks is described as a young and energetic Democrat in the mold of freshman Rep. Kirsten Gillibrand (D), who represents an adjacent district and who also comes from a prominent Albany-area political family. Morris and Soares could attract support from some of the more liberal, reform-minded elements in the local Democratic organization.

But it also is possible that McNulty may try to have some say in who his successor is. He might promote his sister, Green Island Mayor Ellen McNulty-Ryan (D), or the director of his district office, Charles Diamond (D), who serves as a councilman in the city of Watervliet.

Diamond said Friday that he did not want to comment until after McNulty revealed his plans. McNulty-Ryan is serving in a position that both the Congressman and their father also held.

Some media reports Friday suggested that two Republican assemblymen, George Amedore and Minority Leader James Tedisco, could choose to run for McNulty’s seat. But the district is a Democratic stronghold; it gave Sen. John Kerry (D-Mass.) a 12-point victory over President Bush in 2004 and would probably turn out heavily for Clinton if she becomes the Democratic White House nominee.