Senate Majority Leader Harry Reid (D-Nev.) filed cloture on a transportation technical corrections bill Wednesday, even as Democratic leaders and a bipartisan group of lawmakers seeking an investigation of a controversial earmark remained at odds.

Although early in the day Wednesday it appeared that Oklahoma GOP Sens. James Inhofe and Tom Coburn had agreed to a deal to have the Government Accountability Office conduct an inquiry into how a $10 million earmark was slipped into the 2005 transportation bill after it had been passed by the House and Senate, that proposal now appears to be in jeopardy thanks to objections from some Democrats.

Reid, Speaker Nancy Pelosi (D-Calif.) and Environment and Public Works Chairwoman Barbara Boxer (D-Calif.) have thus far resisted Coburn’s efforts to either create a new bicameral committee to investigate the issue or, more recently, the GAO proposal. Inhofe, the ranking member on Environment and Public Works, has acted as a broker between Coburn and Democratic leaders, aides said.

Coburn has led the charge for an investigation into the earmark, which would benefit a Florida land developer connected to Rep. Don Young (R-Alaska), who at the time was chairman of the House Transportation and Infrastructure Committee. Coburn has the support of Florida Sens. Mel Martinez (R) and Bill Nelson (D), as well as that of the three presidential hopefuls: Sens. Barack Obama (D-Ill.), John McCain (R-Ariz.) and Hillary Rodham Clinton (D-N.Y.).

Because cloture will not ripen until Friday morning unless a unanimous consent deal can be reached, Reid’s decision could set the stage for a rare busy Friday for his colleagues, who normally clear out of the Senate late Thursday or early Friday.

The Senate cast its first vote on the bill Wednesday afternoon since taking it up Monday, handily defeating a motion to recommit the multimillion-dollar measure to Environment and Public Works by a vote of 78-18. The motion had been sponsored by Sen. Jim DeMint (R-S.C.), who has criticized spending in the bill.