From NBC's Mike Viqueira
The price tag on the massive Capitol Visitors Center project is likely to go up yet again, according to figures supplied by the Government Accountability Office to congressional officials yesterday. Per congressional sources, the new estimate of the total cost of the project will be between $580 and $600 million. The last GAO estimate -- released in February of this year -- placed the cost at $555 to $584 million.

The CVC has two primary functions. First, it is expected to make the Capitol itself more secure by providing an entry checkpoint at a significant remove from the building. Second, the hope is that it will enhance the experience of the millions who visit each year with exhibitions, an amphitheater, cafeterias, and other amenities. Constructed completely underground, it is the biggest addition to the Capitol since the 1850's, when the current House and Senate chambers, as well as the signature dome and Rotunda, were added to the building.

The CVC was originally projected to come in at $265 million when ground was broken back in 2002. Since then, construction delays and requests by members of Congress for additional space adjacent to the CVC have driven costs upward. Accusations of mismanagement have been directed at the Architect of the Capitol and others involved in managing the project.

In addition, the GAO will also report that the CVC won't open for business until October 2007 at the earliest, five months later than their last estimate. Problems with emergency evacuation plans are cited as a significant factor here. Both the increased cost and delayed opening date are expected to be announced at a Senate hearing this Thursday.