The US House of Representatives has decided mass collection of phone records of American citizens is crucial to fight against terrorism and will continue.
Backed by 205 representatives and rejected by 217, the data protection amendment vote represented the first opportunity for US legislators to take a stand on the secret surveillance programme exposed internationally by former NSA analyst Edward Snowden.
The amendment, put forward by Republican Representative Justin Amash, was intended as an addition to a $598bn (£390bn) defence spending bill for 2014.
Amash said his effort aimed at defending the US Constitution and “the privacy of every American".
However, the measure has encountered strong opposition on all fronts, including the Senate, the Obama administration and the national security leaders.
"Have 12 years gone by and our memories faded so badly that we forgot what happened on September 11?," Mike Rogers, the Republican chairman of the intelligence committee, said in pleading with his colleagues to back the programme.
During the debate in the Republican-controlled House, James Clapper, the director of US national intelligence has warned that dismantling the programme would make the country rather vulnerable.
The extensive surveillance programme, including mass collection of phone records in the US and Internet data gathering all over the world, was approved after the September 11 terrorist attacks. Since then, it has been calimed by its defenders, it helped to prevent at least 50 terror plots in 20 countries, including a 2009 plan to hit the New York Stock Exchange.
After the disclosure earlier this year, many politicians have voiced their concern privacy protection rights had been breached.
Before the vote on the amendment was taken, the White House and the director of the NSA, Army General Keith Alexander, made last-minute appeals to representatives, urging them to oppose it. Eight former attorney generals, CIA directors and national security experts wrote in a letter that the two programmes are fully authorised by law and "conducted in a manner that appropriately respects the privacy and civil liberties interests of Americans".