WASHINGTON (AP) _ Saying that the commission is acting beyond its authority, two key senators are trying to stop the Federal Communications Commission plan to require broadcasters to provide political candidates with free air time.

Sens. John McCain, R-Ariz., and Conrad Burns, R-Mont., said Tuesday that they intend to attempt to attach an amendment blocking the FCC's plans to any emergency spending bill the Senate considers.

McCain is chairman of the Senate Commerce Committee and Burns is chairman of the panel's communications subcommittee. Both have jurisdiction over the FCC.

The FCC is drafting proposals that would either require broadcasters to provide free time or to give deeper discounts on ads than they do now.

Broadcasters face the new requirements as a condition of getting a TV license or renewing one. The broadcasting industry opposes both proposals.

``Mandating free broadcast time cannot and should not be done by a regulatory agency,'' McCain said. ``The FCC is clearly overstepping its authority here.'' Burns agreed.

FCC Chairman Bill Kennard contends that the FCC does have the legal authority to require broadcasters to provide free time. Even though two of the FCC's five commissioners disagree with Kennard's assessment, the chairman has the necessary support among the rest of the commissioners to proceed.

The FCC's proposals, which have not been released, respond to President Clinton's call for such action in his Jan. 27 State of the Union address.