WASHINGTON — Senators who want to use filibusters to block action would have to keep speaking or lose some of the delays built into Senate rules under a “Mr. Smith bill” introduced Wednesday by Sen. Frank Lautenberg.

The proposal, which would need 67 votes for passage, is a long shot in today’s gridlocked environment. But if it were in place, there would be less C-SPAN coverage of an empty Senate chamber caused by a countdown built into the rules before a vote could happen.

“If any of my colleagues feel strongly enough about a bill or nomination to stop all work in the Senate, they should have no problem standing on the Senate floor to explain their opposition to the American public,” said Lautenberg, D-N.J.

Actor James Stewart immortalized the filibuster in the film “Mr. Smith Goes to Washington” by delivering a marathon speech against a corrupt land deal until he collapsed with exhaustion.

The Senate no longer operates that way, however. Instead, it relies heavily on unanimous consent to waive rules and advance motions, nominations and bills. Under the system, a single member can block something without stating a reason, and often without being identified.

To get around such an objection, the majority usually seeks to invoke “cloture” to end debate, and a clock begins ticking. A cloture motion made on a Monday cannot be brought up for a vote until one hour into the session beginning on Wednesday, even if no debate happens in the intervening time.

Lautenberg’s proposal would eliminate that delay if no one comes to the floor to speak, but it would preserve the requirement that 60 votes would be needed to invoke cloture. It would also reduce the 30-hour period that must elapse between approval of a cloture vote and the actual final vote on some measures.

Lautenberg acknowledged supporting filibusters in the past to block nominees and bills.