WASHINGTON - An expansive package of mine and worker safety reforms was approved by a House of Representatives committee Wednesday amid a bitter partisan dispute.

The 30-17 party-line vote in the Education and Labor Committee sent the bill to the House floor, where Chairman George Miller, D-Calif., said he hoped for swift consideration in the wake of the Upper Big Branch mine explosion in West Virginia that killed 29.

But a tortoise pace in the Senate - where Democrats and Republicans plan to work through the August recess in search of a bipartisan compromise - called into doubt when and if the bill will become law.

"I will, perhaps for the first time ever, suggest we look to the Senate for guidance," said Minnesota Rep. John Kline, the committee's top Republican. He objected to the bill's aggressive and broad worker safety provisions and to granting the federal Mine Safety and Health Administration more powers in light of the agency's shortcomings that were exposed by Upper Big Branch.

Mr. Miller later quipped, "This committee is not going to set its markup schedule based on the whims of the Senate that change every day. It would be impossible to do that."

Changes to the bill - which is named for the late Sen. Robert C. Byrd, D-W.Va. - submitted by Mr. Miller on Wednesday included a penalty targeted at disabling safety equipment, which was in response to reports by the Post-Gazette and National Public Radio that an electrician at Upper Big Branch was ordered to disable a methane detector to keep a continuous mining machine operating. The Feb. 13 incident occurred nearly two months before the explosion in a different part of the mine.

The bill's scope was also narrowed significantly with respect to mining: It now applies only to underground coal mines and other underground mines in which explosive gases can be found - leaving the laws governing surface mines and underground mines of most minerals untouched.

A section defining a serious and substantial violation as one which has "a reasonable possibility of an injury, illness or death" was removed, leaving the status quo in place for MSHA and the courts to define "S&S" violations. This came even though MSHA head Joe Main specifically praised the new legislative clarity for S&S citations at a hearing last week.

But the changes do further strengthen MSHA's ability to shut down a mine with a "pattern of violations" - counting accidents as well as citations in the calculations for pattern status and requiring MSHA to screen mines for pattern status at least once every six months.

In a statement, Secretary of Labor Hilda Solis, whose department includes MSHA, called the bill "an important step forward in strengthening safety laws for our nation's miners" and urged passage before the August recess.

Mr. Miller's staff circulated a letter from J. Brett Harvey, the CEO of Bethel Park-based coal producer Consol Energy, thanking Mr. Miller for the chance to review the bill and praising the changes. Still, Mr. Harvey did not fully back the legislation.

"While we appreciate your willingness to consider our proposals, some additional work needs to be done," Mr. Harvey wrote. "Although we cannot endorse the bill at this time, we believe the Manager's Amendment provides a framework for further improvement and ultimate passage of a strong and effective mine safety bill in this Congress that will significantly reduce the likelihood of future mine disasters."

Luke Popovich, spokesman for the National Mining Association, said the group will not support the bill.

Republican objections to the bill focused primarily on its changes to the Occupational Health and Safety Act, which they complained were overly draconian and out of place in a bill that is meant to address mine safety.

The bill would increase penalties against all employers for safety violations and give additional whistle-blower protections to employees, including allowing them to pursue their complaints on their own even if they are turned down by the Occupational Safety and Health Administration.

Committee Republicans offered a scaled-back bill that shared many of the mine safety reforms of Mr. Miller's bill; Rep. Shelley Moore Capito, R-W.Va., who is not on the committee, also introduced her own standalone legislation this week focused on mining that was more prescriptive in defining pattern of violation status.

Democrats, meanwhile, said the changes were long overdue and said the deaths on the BP oil rig in the Gulf of Mexico and other recent workplace fatalities were more than enough impetus for an aggressive response.

In a rare point of bipartisan comity, Rep. Jason Altmire, D-McCandless, emphasized the need for MSHA to return to its pre-2008 practice of holding conferences with operators after issuing a citation in the hopes of resolving it before a legal challenge. Mr. Altmire said he refrained from introducing an amendment on the subject because MSHA has pledged to roll out a pilot program next month to bring back the conferences in an effort to reduce the massive backlog of citation challenges that has overwhelmed the system.

After Mr. Altmire laid out his conference position, Mr. Kline responded, "He's exactly correct."

The day ended with Democrats united in favor of the bill and all the committee Republicans against it. Among the Pennsylvania delegation, Mr. Altmire and Rep. Joe Sestak, a Democrat from outside Philadelphia who is running for Senate, voted in favor of the bill. Rep. Glenn Thompson, R-Centre, voted no.

Washington correspondent Daniel Malloy writes the "Pittsburgh On The Potomac" blog exclusively at PG+, a members-only web site of the Pittsburgh Post-Gazette. Our introduction to PG+ gives you all the details.