The U.S. House of Representatives upped the ante today in its on-going investigation of the scandal surrounding the fired U.S. Attorneys. Contempt resolutions against top Bush aides Josh Bolten and Harriet Miers passed:

The House voted Thursday to hold White House Chief of Staff Josh Bolten and former White House counsel Harriet Miers in contempt of Congress for refusing to testify before a panel investigating the firing of several United States attorneys.

Ahead of the vote, Republicans had walked out in an effort to show that they want to work on a permanent update to the Foreign Intelligence Surveillance Act (FISA) rather than be part of a “partisan fishing expedition,” as House Minority Leader John Boehner (R-Ohio) put it.

The contempt vote raises the stakes between the White House and Congress in the battle over the fired U.S. attorneys and could set up a constitutional showdown between the legislative and executive branches.

The matter will now be referred to the U.S. attorney for the District of Columbia.