Reply #31: It looks like it's unconsitutional:

[Cameron27]

"On the first day of my administration, I will submit legislation that ends health care coverage for the president, all members of Congress, and all senior political appointees in both branches of government on July 20th, 2009 -- unless we have passed universal health care reform."

"There’s already some chatter in the blogosphere about the possibly dubious constitutionality of this idea, at least as it applies to members of Congress. (The 27th Amendment says, “No law, varying the compensation for the services of the Senators and Representatives, shall take effect, until an election of Representatives shall have intervened.”)

“Senior political appointees,” though, could be out of luck. But maybe Schedule Cs will get to keep their coverage."

FedBlog

http://blogs.govexec.com/fedblog/2007/09/no_health_care_for_appointees.php