The Prime Minister, who issued a "full and frank apology" for hiring Coulson, is set to face a Labour onslaught at Commons question-time to justify why, despite concerns raised by political friends and foes, he placed one of Rupert Murdoch's key executives at the heart of government as his director of communications.
Coulson, 46, looked ashen-faced as he left the Old Bailey last night, ignoring questions from journalists as he stepped into a black cab.
Earlier, his predecessor at the NotW and former lover, Rebekah Brooks, also 46, walked free from court after being cleared unanimously of all four of the charges she faced during the eight-month trial.
As the verdicts were read out in Court Number 12, Mrs Brooks looked stunned, shook visibly and was led away by a nurse. Coulson remained impassive.
Later, Mrs Brooks emerged from court and walked through a scrum of photographers, clutching the hand of her racehorse trainer husband, Charlie, 52, who was also cleared of attempting to hinder the police investigation.
There are still outstanding charges facing Coulson and former NotW royal editor Clive Goodman, 56, of conspiring to commit misconduct in a public office by paying police officers for two royal directories. Both deny the charges.
The judge, Mr Justice Saunders, called for restraint after political reaction spread following the guilty verdict.
As the jury was sent home, having failed to reach verdicts on the outstanding charges, the judge urged them to ignore the "huge amount of comment out there" and "decide this case on the evidence and the evidence alone".
Earlier in Downing Street, Mr Cameron issued a "full and frank apology" for hiring Coulson, saying: "I am extremely sorry that I employed him. It was the wrong decision and I am very clear about that."
Pressed over the precise questions he had put to Coulson when interviewing him for the job, the PM replied: "I asked him questions about whether he knew about phone hacking and he said he didn't and I accepted those assurances and I gave him the job."
Stressing no-one had complained about Coulson while he was Mr Cameron's chief spin doctor either at Tory HQ or then in No 10, the PM added: "But knowing what I now know, and knowing that the assurances were not right, it was obviously wrong to employ him. I gave someone a second chance and it turned out to be a bad decision."
But the apology was not enough for Ed Miliband, who accused Mr Cameron of bringing a "criminal into the heart of Downing Street".
"This isn't just a serious error of judgment," said the Labour leader. "This taints David Cameron's government because we now know that he put his relationship with Rupert Murdoch ahead of doing the right thing when it came to Andy Coulson."
Mr Miliband noted how there were many warnings about the ex-tabloid editor but the Prime Minister chose to dismiss them. "David Cameron must do much more than an apology. He owes the country an explanation for why he did not act on these allegations against Andy Coulson, why as the evidence piled up he didn't do anything about them."
Lord Prescott, who was targeted by the NotW while he was in the Labour government, said: "Cameron's apology today is the very minimum he could do. But his blind acceptance of Coulson's innocence, with next to no due diligence, exposes his appallingly poor judgment."
For years, News International insisted the crime of phone hacking was limited to a single rogue reporter and aggressively rejected any suggestions otherwise.
But police believe there were probably more than 1000 victims whose voicemails were hacked, including one belonging to murdered schoolgirl Milly Dowler.
Other victims included Princes William and Harry, Kate, the Duchess of Cambridge, politicians such as David Blunkett, the former Home Secretary, actors such as Sienna Miller and Daniel Craig, prominent sporting figures and even rival journalists. They were all targeted in a desperate attempt to find exclusive stories for the now defunct top-selling newspaper.
Following Coulson's conviction, Mr Blunkett said: "No-one should misinterpret what has happened as an indictment of a free press or of the professionalism of most trained and dedicated journalists. Nor should they see this as vengeance on the media as a whole or even one particular publisher.
"This was and remains a matter of criminality, of gross intrusion into the private lives of innocent people and a distortion and aberration of everything that high standards of journalism stand for."