Long-serving King County Executive Ron Sims (D-Seattle) may face a challenge from within his own party in next year's race for the urban county's highest seat. The Seattle Times' David Postman reports that King County Councilman Larry Phillips (D-Seattle) has started an official exploratory committee to raise money and consider his chances for King County Executive.

"Running for County Executive is a big undertaking and one I do not take lightly," Phillips told supporters in an e-mail obtained by the Times. "I have a deep respect for the incumbent, as he's done many good things in King County, and I realize that it's hard to move on. But 13 years in office - with an unprecedented fourth term on the horizon - is a long time."

Phillips also went on to suggest that Sims' leadership may no longer be as effective as it should be. Last week the Times also reported that the relationship between Sims and Phillips has been "souring for some time."

UPDATE: The full e-mail from Phillips can be seen here.