U.S. House Majority Leader Rep. Eric Cantor (R-Va.) speaks. (Alex Wong/Getty Images)

During the news conference, which House Majority Leader Eric Cantor (R-Va.) will also attend, Republicans are expected to blast the Obama administration over looming defense cuts.

The meeting — an annual gathering of the governor and members of the Senate and House — is scheduled for 1:30 p.m. on Capitol Hill. The partisan news conference was announced by the governor’s office late Tuesday and scheduled for 2:40 p.m. after the hour-long meeting.

At noon, just hearing word of the boycott from a reporter, Republicans moved the location.

Updated, 2:30 p.m.: The news conference was canceled, though McDonnell will speak to reporters briefly.

The state’s two Democratic senators and three Democratic congressmen — U.S. Sens. Jim Webb (D-Va.) and Mark R. Warner (D-Va.) and U.S. Reps. Jim Moran (D-Va.-8), Bobby Scott (D-Va.-3) and Gerry Connolly (D-Va.-11) — issued a statement later in the day:

“Today’s approach to what has always been a bipartisan discussion simply is not the Virginia way. For decades, the Virginia congressional delegation has had a tradition of productive, bipartisan meetings with a long line of recent governors, Republican and Democrat. At these meetings and thereafter, partisan politics always took a back seat to our combined efforts to move Virginia forward. Today’s delegation meeting was derailed by Republican efforts to apply a partisan spin to the discussion and to the issues that face us.  We reject this approach and find it to be contrary to Virginia’s long traditions in such matters.”

 Sequestration, the term for the bipartisan cuts called for by last year’s debt-ceiling deal, has emerged as an issue on the campaign trail, including military-vote-rich Virginia.

Congress passed the Budget Control Act in August, raising the federal debt ceiling and pledging to cut budget deficits by at least $2.1 trillion from 2012 to 2021.

The first $50 billion worth of cuts is set to take effect in January 2013. Some defense contractors have said they will be forced to issue layoff notices to workers 60 days before the cuts are enacted, days before the Nov. 6 election.

Congress created a “supercommittee” to achieve the remaining $1.2 trillion of deficit reduction through more spending cuts or tax increases.

All Republicans except Reps. Morgan Griffith and Randy Forbes voted for the bill.

“The Democrats put election-year politics ahead of governing today,’’ McDonnell spokesman Tucker Martin said. “They put unprecedented conditions on their attendance at what is a long-standing, bipartisan annual meeting. Even when they got what they wanted, they boycotted the meeting nonetheless. It was politics at its worst, and Virginians deserve far, far better.”