The report by the non-partisan Government Accountability Office said that mine operators need better guidance from the Mine Safety and Health Administration on how detailed the emergency response plans should be and, as a result, it is "uncertain whether all miners will be adequately protected in the event of an accident."

The GAO also said supply shortages have kept some mines from providing adequate emergency air supplies and MSHA has not exercised its authority to require mines to install emergency communications systems until a totally wireless network is available.

Rep. George Miller, D-Calif., chairman of the House Labor Committee, said the failure to follow through on the post-Sago reforms is "outrageous."

"Under the Bush administration, MSHA continues to fail to act despite the many promises made to miners and their families on the lessons learned from mining tragedies over the last two years," Miller said in a statement.

But MSHA said any shortcomings are due to technology, not bureaucracy.

"Apparently, George Miller did not want the facts of the report he commissioned to get in the way of his headline-grabbing remarks," said MSHA spokesman Matt Faraci.

Faraci said a wireless network is not yet feasible and adequate breathable air equipment is in short supply, but emergency plans have, otherwise, been implemented.