Republican proposals to improve U.S. auto safety came under fire on Tuesday from federal regulators, who warned that proposed changes to current rules would erode consumer safety and give automakers control over the public disclosure of safety recalls.

In written testimony submitted to the House Energy and Commerce Committee, officials from the National Highway Traffic Safety Administration and Federal Trade Commission also took issue with draft legislation to let a new industry-dominated advisory council set best practices for protecting car owners from cyber attacks.

“The proposals could seriously undermine NHTSA’s efforts to ensure safety,” NHTSA Administrator Mark Rosekind said.

Written testimony from Rosekind and FTC official Maneesha Mithal was posted to the committee’s website ahead of a Wednesday hearing on a 62-page draft bill intended to upgrade auto and highway safety after a string of auto safety defects, including deadly General Motors Co ignition switches and Takata Corp air bag inflators.

The wide-ranging legislative proposal, which the House Energy and Commerce Subcommittee on Commerce, Manufacturing and Trade is considering, is intended to prepare regulators for a new generation of automotive technological innovation by amending a host of areas, from agency reporting requirements and safety recall procedures to privacy, cyber attacks and safety information.

Rosekind, who has taken a tougher approach to automakers since taking over NHTSA less than a year ago, said the draft would require regulators to withhold safety recall notices from the public until a manufacturer has identified all vehicles affected by a defect.

“This proposal impinges on the agency’s enforcement authority and is in direct conflict with other congressional interests to increase the transparency of safety information,” he said in the testimony.

Mithal, associate director of the FTC’s Privacy and Identity Protection Division, said the proposals would also exempt automakers from regulatory oversight and penalties involving their handling of consumer data.

Both Mithal and Rosekind took issue with a proposal to establish an Automotive Cyber Security Advisory Council to develop best practices for cyber security, saying the plan would give half the council seats to the auto industry while relegating other stakeholders to one seat each.

Testimony from two auto industry officials, who are also scheduled to testify, said carmakers have taken unprecedented steps to protect consumer privacy and enhance safety recall completion rates and have begun working to develop new cyber security standards and guidelines for the entire industry.