More than 5,500 legislators and legislative staff from state capitals nationwide will begin convening in Philadelphia Sunday for a weeklong national conference.

But not a single Pennsylvania lawmaker is likely to be among them.

That wasn't in the original plan when the annual meeting of the National Conference of State Legislators was booked here several years ago.

But even though Pennsylvania is the conference's host state, members of the General Assembly Saturday appeared destined to spend the upcoming week under the Capitol dome in Harrisburg - mired in a budget impasse and unable to join their counterparts at more than 150 government symposiums, forums with two Obama Administration officials, a Patti LaBelle concert at the Philadelphia Museum of Art and a baseball game between the world champion Phillies and the Chicago Cubs.

"As far as the speaker is concerned, and the lawmakers, the top priority is getting the budget done, and if we do that, we'll get people down there as soon as we can," Bob Caton, spokesman for Pennsylvania House Speaker Keith McCall (D,. Carbon), said.

But the chances of that happening diminished throughout last week. On Wednesday, the speaker distributed a memo saying Democratic members needed to be on hand to vote in case a final budget deal emerged. By Friday, every House member registered to go had cancelled, Caton said.

That included McCall, who had been scheduled to introduce Microsoft founder Bill Gates for a speech Tuesday on "A Bold New Vision for Education." Consequently, Caton said, "We're trying to get the speaker of the North Carolina House to do it."

While the plans of Senate Democrats were unclear - Sen. Sean Logan, the minority caucus secretary, did not return a call - a GOP spokesman said no Senate Republicans were scheduled to leave Harrisburg.

That would leave Pennsylvania to be represented by a few dozen legislative staffers whose work has nothing to do with anything budgetary - and hence, their permission to attend the meeting in Philadelphia.

Another thing that's changed in the time since the conference was planned: Philadelphia's economy stands to benefit less.

Initial projections had conference attendees spending $23 million on, primarily, hotels, restaurants and shopping. That estimate has now dropped to $14 million, largely because of shorter hotel stays that are expected, according to Caton.

Even entertainment costs have been scaled back, with total spending anticipated to be $795,000. That would mean spending $140,000 less than last year's conference in New Orleans, and $400,000 less than the conference held two years ago in Boston.

The conference, which is slated to end Friday, takes place at the Pennsylvania Convention Center. Its major theme concerns the economy and its impact on states. Other topics to be discussed - in between forums on "What's New with Constituent Services" and "Election Reform Roadmap" - include transportation, national security, the environment and education.

Besides touring the Port of Philadelphia and the Library Company of Philadelphia, attendees will also have a chance to hear from U.S. Commerce Secretary Gary Lock, who on Thursday is scheduled to talk about the census, and U.S. Health and Human Services Secretary Kathleen Sebelius, who on Friday is expected to speak about healthcare reform.

Legislators were also invited to paint a mural that will be donated to Philadelphia's VA Medical Center.

Contact staff writer Marcia Gelbart at 215-854-2338 or mgelbart@phillynews.com.