UPDATE: Fox News has just learned that Stupak will NOT resign.  According to his congressional district director, Rep. Stupak will only announce today that he is not seeking re-election.

Fox News has learned that President Obama called Rep. Bart Stupak, D-Mich., a few days ago and implored him not to retire.

It is thought among some Michigan political leaders that Stupak could announce he is RESIGNING today, not just retiring at the end of his term early next year.

There is a concerted effort now underway by senior democratic officials to keep him in office for at least the rest of this term. Stupak has been in office since 1992..and given its rural leanings, it could very well flip to Republicans.

Democratic officials are concerned about the possibility of a third special election if Stupak were to leave early.

For starters, they have a real dogfight going on among democrats to succeed former Rep. Neil Abercrombie, D-Hawaii, who resigned at the end of February.

Democrats are wary about losing the seats once held by the late Rep. Jack Murtha, D-Pa., who died in February...and the seat held by former Rep. Eric Massa, D-N.Y., who resigned last month. The thought is that three competitive special elections in a tough election year could really do Democrats in.