The prime minister has called on former Sun editor Kelvin MacKenzie to "face up to his own responsibilities" over the paper's coverage of the Hillsborough tragedy.
David Cameron was speaking to MPs after revealing the contents of the Bishop of Liverpool's inquiry into the disaster, which revealed police and emergency services made "strenuous attempts" to deflect the blame for the deaths of 96 Liverpool fans at Sheffield Wednesday's Hillsborough stadium on 15 April 1989.
Four days after the tragedy, The Sun, then edited by MacKenzie, published a front page story headlined 'THE TRUTH.'
It alleged fans urinated on police, stole from the dead and beat up rescue workers, citing police sources and the then Conservative MP for Sheffield, Irvine Patnick.
The story itself alleged a "mob" joked about molesting a dead girl, and quoted a high ranking police man saying: "The fans were just acting like animals. My men faced a double hell - the disaster and the fury of the fans who attacked us."
The reporter who wrote the front page story, Harry Arnold, later said he regretted the headline, which he insisted was MacKenzie's, but said he had written the story in a "fair and balanced" way.
The story prompted a boycott of The Sun in Liverpool, which remains to this day, despite the newspaper apologising for the "terrible mistake" in 2004.
But the paper's move was rebuffed by the chairman of the Hillsborough family support group Phil Hammond, who said "It wasn't an apology, it was an excuse to have a pop at Liverpool."
Controversy: There is a widespread boycott of The Sun in Liverpool
Speaking to MPs on Wednesday Cameron condemned The Sun's "appalling article", as MacKenzie's name began to trend on Twitter.
"My view is that Kelvin MacKenzie needs to take responsibility for that," he said. "Lots of apologies have been made but we've now good a definitive guide to what happened... Sorry isn't good enough unless you understand what you've actually done."
Labour leader Ed Miliband told the Commons The Sun should apologise to the families of the dead, while Labour MP Chris Bryant called on MacKenzie to apologise.
Despite MacKenzie saying the coverage was a "fundamental mistake" in 1993, he appeared to backtrack in 2006, telling a business lunch he was "not sorry then and I'm not sorry now."
"All I did wrong there was [to] tell the truth."
He has yet to make a public comment on Wednesday, despite calls for news organisations to boycott using him as a pundit unless he apologises.