White House hopeful Rand Paul has theatrically brought the US Senate to a standstill, delivering a 10-hour, 30-minute speech seeking to end intelligence agency bulk telephone data collection from millions of Americans.

The Republican senator from Kentucky said he launched his filibuster, a talkathon that stops other action in the Senate, to prevent powerful legislators from ramming through a two-month extension of the law that would reauthorise the controversial collection of phone data.

“There comes a time in the history of nations when fear and complacency allow power to accumulate and liberty and privacy to suffer. That time is now, and I will not let the Patriot Act – the most unpatriotic of acts – go unchallenged,” Paul said at the start of his speech on Wednesday.

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Paul has made reining in government surveillance a key part of his presidential platform.

The speech was the chamber’s longest since fellow Republican Ted Cruz held the floor for 21 hours in 2013 to protest President Barack Obama’s health care reforms.

Paul’s take-over of the Senate schedule came as the chamber considered trade legislation.

Despite its length, the speech did not ultimately delay votes.

But Paul’s tactics highlighted the first-term senator’s ability to command attention on an issue that he and others think has been pushed to the side by Republican Majority Leader Mitch McConnell, who would rather extend the current law than make changes.

More than a dozen senators, including several Democrats, participated in the talkathon, asking Paul questions and giving the lawmaker welcome breaks from speaking.

Democrat Martin Heinrich weighed in to describe a “critical turning point” in the Patriot Act, and thanked Paul for his speech that will “force us all to have this conversation”.

Noting how a federal appeals court last month declared the data sweep unlawful, “why on Earth would we extend a law that this court has found to be illegal?” Heinrich asked.

The law’s section which allows bulk collection, as well as provisions authorising roving wiretaps and lone-wolf tracking, expire June 1.

Last week the House of Representatives passed legislation that ends the National Security Agency’s dragnet collection of telephone data, including time and duration of calls but not content.

The bill replaces that with measures allowing authorities access to phone data of specific terror suspects, but only with a warrant from a special judge.

Senate leaders have yet to bring that bill, the USA Freedom Act, up for consideration.

Paul, citing what he called “the right to be left alone”, opposes those reforms too, arguing they leave open the possibility of scooping data from large groups of innocent Americans.