Piers and Mr Campbell found themselves in yet another argument over the latter's time as spin doctor for Tony Blair’s Labour government. It came as Sky News’ Julia Hartley-Brewer attempted to defend the media over the passing of well-known TV presenter, Caroline Flack.
Ms Hartley-Brewer wrote: “The angry keyboard warriors accusing people in the media of hounding Caroline Flack to her death are very same people who incessantly post abuse to celebrities & people in the media - & who are right now busily hounding those same people online.
“Different rules, I guess…”
To this, Mr Campbell replied: “Suggest you and Piers Morgan have a day off.”
Piers was quick to respond to the calling out, and tweeted Mr Campbell: “YOU are lecturing people about how to engage on social media?
The pair were engaged in a fierce debate on Twitter over Iraq and the media
Campbell was Tony Blair's spin doctor and is largely considered as the mastermind behind New Labour
“A man who spun this country into an illegal war & who spews constant hateful abuse about anyone who doesn’t share his political views? Irony is truly dead.”
It was a reference to Mr Campbell’s time as Mr Blair’s spin doctor.
In 1994, Mr Campbell left his job as news editor at Today in 1994 to become the press secretary of Mr Blair.
He rose to prominence, being credited with coining the term “New Labour” and writing the speech that led to the party’s review of Clause IV, and the subsequent birth of a new kind of party.
JUST IN: Nigel Farage mocks 'twisted' Adonis and Campbell in Brexit coin rant
the Iraq war lasted eight years with thousands of soldiers and civilians losing their lives
He played a crucial role in securing Labour’s successful election campaign in 1997.
And, by March 1997, his work within renewing Labour led to many leading newspapers pledging their support for Mr Blair and Labour - including The Sun.
In the run-up to the Iraq War, Mr Campbell was involved in the preparation and release of the September Dossier.
The dossier was part of an ongoing investigation by the government into alleged weapons of mass destruction in Iraq, and ultimately led to the 2003 invasion of Iraq.
Meghan Markle and Prince Harry’s huge flaw in plan exposed [LATEST]
Panel in stitches as Jeremy Vine mocks Jacob Rees-Mogg with outburst [UPDATE]
Brexiteers mock Alastair Campbell over refusal to use 50p Brexit coin [ANALYSIS]
Campbell and Cherie Blair, Tony's sister
The September Dossier has since been scrutinised for being misleading and distorting the truth
The dossier and investigation have since been criticised as overstating or distorting the actual intelligence findings.
It led to the claim that Iraq was seeking to buy uranium from Africa, a statement which was reported in US President George W. Bush’s 2003 State of the Union Address.
Yet, in March 2003, the International Atomic energy Agency (IAEA) eventually obtained documents the US referred to in making this claim, and concluded they were obvious fakes.
Mr Campbell has since worked to defend his corner in claims and allegations against him.
The world's largest militaries
In 2011, shortly before the end of the Iraq war - that spanned eight years - Major General Micheal Laure disputed Mr Campbell’s claim that the September Dossier was not meant to “make the case for war”.
He told the inquiry those producing the dossier "saw it exactly as that and that was the direction we were given".
Mr Campbell, however, said those "directly involved" in producing the dossier had backed him.
The Iraq inquiry examined events between 2001 and 2009, including the decision to go to war, post-invasion planning, what lessons were learned, and whether troops were properly equipped.
Iraqi prisoner's of war during the invasion in 2003
In the inquiry, Maj Gen Laurie wrote: "Alastair Campbell said to the inquiry that the purpose of the dossier was not to "make a case for war.
"I had no doubt at this time this was exactly its purpose and these very words were used."
He said a similar document produced six months earlier had been rejected as it had "not made a strong enough case".