In the first comments from al-Qa'ida since the American elections, the second-in-command of the terror group has branded President-elect Barack Obama as a "house negro", an insult designed to imply he is a black man merely doing the bidding of white masters.

Ayman al-Zawahiri, al-Qa'ida's deputy leader, also mocked Mr Obama as being the "direct opposite of honourable black Americans" such as Malcolm X, the Muslim African-American rights leader of the 1960s.

As a welcome message to the soon-to-be president, it was predictably aggressive and belligerent, though it contained no specific threats of attack. "You have reached the position of president, and a heavy legacy of failure and crimes awaits you. A failure in Iraq to which you have admitted, and a failure in Afghanistan to which the commanders of your army have admitted."

The message was a clear attempt to dampen global enthusiasm after the election of Mr Obama and the attendant hopes that his taking office in January will spell a fundamental shift in American foreign policy, already highlighted by his renewed promises to close Guantanamo Bay and begin the troop withdrawal from Iraq.

There seemed little initial reason to doubt the authenticity of the message posted on the web or that that isZawahiri speaking. Accompanying the 11-minute taped audio was footage of Malcolm X, still images ofZawahiri and also of Mr Obama, including one of him wearing a Jewish skull cap during a visit to Israel. The message, posted on jihadi web forums and entitled "The departure of Bush and the arrival of Obama", was condemned by the outgoing administration of George Bush. Sean McCormack, the State Department spokesman, said it only amounted to just "more despicable comments from a terrorist".

Zawahiri used the term abeed al-beit to insult Mr Obama as well as Condoleezza Rice, the outgoing Secretary of State, and her predecessor, Colin Powell, which translates as "house slaves". The English subtitles on the posting turned it into "house negroes", however, a term that Malcolm X used to employ about black leaders he believed were not standing up to whites.

The attempt by al-Qa'ida to expropriate the memory of Malcolm X and uphold him as more worthy than Mr Obama will infuriate the black community in America.

The message sought, however, to address Muslims around the world as much as it did the United States, seeking to warn them against being lulled into the belief that, by electing Mr Obama, America was changing policy direction or altering its attitudes to the rest of the world.

"America has put on a new face but its heart is full of hate, mind drowning in greed, and spirit which spreads evil, murder, repression and despotism continue to be the same as always," the al-Qa'ida deputy insisted. Zawahiri also attempts to characterise the victory of Mr Obama in the US elections as an acknowledgement by Americans that Mr Bush's policies had failed and an "admission of defeat in Iraq". "If Bush has achieved anything, it is in his transfer of America's disaster and predicament to his successor. But the American people, by electing Obama, declared its anxiety and apprehension about the future towards which the policy of the likes of Bush is leading it, and so it decided to support someone calling for withdrawal from Iraq."

He assails Mr Obama for pledging to redeploy some of the troops in Iraq to Afghanistan, insisting his strategy in the country is doomed to fail and he would be rewarded with humiliation in the same way as Mr Bush and Pervez Musharraf. "Be aware that the dogs of Afghanistan have found the flesh of your soldiers to be delicious, so send thousands after thousands to them," he said.

Despite the President-elect never having been a practising Muslim,Zawahiri accuses him of having "abandoned" his Muslim faith. "You were born to a Muslim father but chose to stand in the ranks of the enemies of the Muslims, and pray the prayer of the Jews, although you claim to be Christian, in order to climb the rungs of leadership in America," he said.