Singer Zach de la Rocha of Rage Against the Machine, shown in February, said he was 'ecstatic' that Killing in the Name has been chosen as Britain's 2009 Christmas No. 1 song. ((Joshua Lott/Reuters))

Rage Against the Machine's Killing in the Name became Britain's 2009 Christmas No. 1 on the weekend, after being pushed to the top of the charts by a Facebook campaign.

The Climb, a song by Joe McElderry, the winner of British talent show X Factor, looked set to take the No. 1 spot  until a husband and wife team set up a Facebook campaign to root for the Rage Against the Machine song.

The Climb is a feel-good anthem about overcoming adversity by a cleancut young crooner, while Killing in the Name is a distinctly angry tirade by a band known for its protest songs that contains the repeated line "F--- you, I won't do what you tell me."

Its win is considered a major upset in the competition for the top song of Christmas week, a battle that Britons take very seriously.

Killing in the Name, first released in 1992, sold 500,000 downloads, compared to 450,000 for The Climb.

For the past four years, a song from Simon Cowell's talent show X Factor has achieved the No. 1 spot on Christmas week. Winners have include Alexandra Burke singing Hallelujah and Leon Jackson singing When You Believe.

This year Jon and Tracy Morter set out to stop the X Factor juggernaut in early December with their Facebook campaign

"We really love music and remember when we were young the charts were really exciting," Tracy Morter told BBC. "We just thought, wouldn't it be funny if that song [Killing in the Name ] got to Number 1? It took something really strong and forceful to get people behind it."

More than 1.5 million people signed onto the Facebook campaign, a huge grassroots movement motivated mainly by dislike for the dominance of X Factor on the British entertainment scene.

It is the second year the Morters have attempted to skew the Christmas hit list — last year they promoted Rick Astley's Never Gonna Give You Up against X Factor winner Burke.

The battle between Rage Against the Machine and McElderry drew an unusual amount of attention to the British charts this year, with five million tuning in to hear the chart results on Sunday.

Zack de la Rocha from the Los Angeles-based band promised a British concert in 2010 to celebrate the win.

"We are very, very ecstatic about being Number 1," he told BBC, expressing admiration for the "incredible grassroots campaign."

McElderry, 18, said he didn't take the campaign against him personally. He thanked fans who bought his single and said success on X Factor was already more than he had expected.