Con­gress this week qui­et­ly passed a bill that may give unprece­dent­ed legal author­i­ty to the government’s war­rant­less sur­veil­lance pow­ers, despite a last-minute effort by Rep. Justin Amash to kill the bill.

Amash staged an aggres­sive eleventh-hour ral­ly Wednes­day night to block pas­sage of the Intel­li­gence Autho­riza­tion Act, which will fund intel­li­gence agen­cies for the next fis­cal year. The Michi­gan Repub­li­can sound­ed alarms over recent­ly amend­ed lan­guage in the pack­age that he said will for the first time give con­gres­sion­al back­ing to a con­tro­ver­sial Rea­gan-era decree grant­i­ng broad sur­veil­lance author­i­ty to the president.

The 47-page intel­li­gence bill was head­ed toward a voice vote when Amash rose to the House floor to ask for a roll call. Despite his efforts—which includ­ed a “Dear Col­league” let­ter sent to all mem­bers of the House urg­ing a no vote—the bill passed 325–100, with 55 Democ­rats and 45 Repub­li­cans opposing.

The pro­vi­sion in ques­tion is “one of the most egre­gious sec­tions of law I’ve encoun­tered dur­ing my time as a rep­re­sen­ta­tive,” Amash wrote on his Face­book page. The tea-par­ty lib­er­tar­i­an, who teamed up with Rep. John Cony­ers in an almost-suc­cess­ful bid to defund the Nation­al Secu­ri­ty Agency in the wake of the Snow­den rev­e­la­tions, warned that the pro­vi­sion “grants the exec­u­tive branch vir­tu­al­ly unlim­it­ed access to the com­mu­ni­ca­tions of every American.”

The mea­sure already passed the Sen­ate by unan­i­mous con­sent on Tues­day, and it is now on its way to the White House, where Pres­i­dent Oba­ma is expect­ed to sign it.

The objec­tions from Amash and oth­ers arose from lan­guage in the bill’s Sec­tion 309, which includes a phrase to allow for “the acqui­si­tion, reten­tion, and dis­sem­i­na­tion” of U.S. phone and Inter­net data. That pas­sage will give unprece­dent­ed statu­to­ry author­i­ty to allow for the sur­veil­lance of pri­vate com­mu­ni­ca­tions that cur­rent­ly exists only under a decades-old pres­i­den­tial decree, known as Exec­u­tive Order 12333.

“If this hadn’t been snuck in, I doubt it would have passed,” said Rep. Zoe Lof­gren, a Cal­i­for­nia Demo­c­rat who vot­ed against the bill. “A lot of mem­bers were not even aware that this new pro­vi­sion had been insert­ed last-minute. Had we been giv­en an addi­tion­al day, we may have stopped it.”

Lof­gren said she believed the Sen­ate Intel­li­gence Com­mit­tee was the source of the lan­guage. The pan­el did not respond to requests for comment.

Lof­gren also said the lan­guage was “the exact oppo­site of what the House passed this sum­mer.” She was refer­ring to an amend­ment she cham­pi­oned that would have required the NSAto obtain a war­rant before read­ing Amer­i­cans’ pri­vate mes­sages that were col­lect­ed through a pro­gram intend­ed to tar­get for­eign­ers. “Con­gress is autho­riz­ing some­thing very ques­tion­able con­sti­tu­tion­al­ly,” Lof­gren added.

A tech-indus­try lob­by­ist added: “The lan­guage is broad, and depend­ing on how it is imple­ment­ed, does lit­tle to help restore the public’s lack of trust in U.S. gov­ern­ment sur­veil­lance programs.”

Back­ers of the sec­tion argue it would actu­al­ly lim­it to five years the amount of time com­mu­ni­ca­tions data could be kept at intel­li­gence agen­cies, cer­tain excep­tions per­mit­ting. But it is gen­er­al­ly acknowl­edged that such data is already rarely kept beyond five years, which Amash char­ac­ter­ized as a trade-off that “pro­vides a nov­el statu­to­ry basis for the exec­u­tive branch’s cap­ture and use of Amer­i­cans’ pri­vate communications.”

“The pro­vi­sions in the intel autho­riza­tion appear to be an attempt by Con­gress to place statu­to­ry restric­tions on the reten­tion of infor­ma­tion col­lect­ed under Exec­u­tive Order 12333, which is not sub­ject to court over­sight, has not been autho­rized by Con­gress, and rais­es seri­ous pri­va­cy con­cerns,” said Neema Guliani, leg­isla­tive coun­sel with the Amer­i­can Civ­il Lib­er­ties Union. “How­ev­er, these restric­tions are far from ade­quate, con­tain enor­mous loop­holes, and notably com­plete­ly exclude the infor­ma­tion of non‑U.S. persons.”

Exec­u­tive Order 12333 is not as wide­ly known as the con­tro­ver­sial Sec­tion 215 of the USA Patri­ot Act—which allows for the mass col­lec­tion of domes­tic phone meta­da­ta. Like Sec­tion 702 of the For­eign Intel­li­gence Sur­veil­lance Act, 12333 is intend­ed to tar­get for­eign sur­veil­lance, although an unknown amount of U.S. data is “inci­den­tal­ly” tracked, par­tic­u­lar­ly for cit­i­zens liv­ing over­seas or those that com­mu­ni­cate with foreigners.

But the order, which was issued by Pres­i­dent Rea­gan in 1981 and twice amend­ed by Pres­i­dent George W. Bush, earned a burst of atten­tion this sum­mer when for­mer State Depart­ment offi­cial John Napi­er Tye wrote exten­sive­ly about it in the Wash­ing­ton Post.

“Exec­u­tive Order 12333 con­tains noth­ing to pre­vent the NSAfrom col­lect­ing and stor­ing all such communication—content as well as meta­da­ta— pro­vid­ed that such col­lec­tion occurs out­side the Unit­ed States in the course of a law­ful for­eign intel­li­gence inves­ti­ga­tion,” Tye wrote. “No war­rant or court approval is required, and such col­lec­tion nev­er need be report­ed to Con­gress. None of the reforms that Oba­ma announced ear­li­er this year will affect such collection.”

In Sep­tem­ber, four House Democ­rats asked the Oba­ma admin­is­tra­tion to make pub­lic “all cur­rent and future legal opin­ions or inter­pre­ta­tions” con­cern­ing 12333, a request that thus far has gone unheed­ed. In their let­ter, Reps. Cony­ers, Lof­gren, Alan Grayson, and Rush Holt join with a num­ber of pri­va­cy groups to express con­cerns about the order, say­ing that “secret law is a threat to democracy.”

Ear­li­er this year, the Pri­va­cy and Civ­il Lib­er­ties Over­sight Board announced it would begin a review of the legal­i­ty of 12333.

Pres­i­dent Oba­ma in Jan­u­ary promised to reform the NSA’s mass domes­tic spy­ing, but he said he would wait for Con­gress to enact broad­er reforms. A bill intend­ed to rein in sev­er­al aspects of gov­ern­ment sur­veil­lance died in the Sen­ate last month, falling two votes short of the 60-vote thresh­old need­ed to advance.