The argument started after Ingham responded to a tweet asking if Phillips' view that PR is dead was correct.
Phillips responded saying that Ingham had been "speaking to his navel again", to which Ingham reeled off the membership numbers of the PRCA and International Communications Consultancy Organisation.
The two continued batting their views back and forth, with Phillips stating: "Metrics irrelevant. Accountability more important."
Then the Twitter spat moved away from facts and figures and started to get personal:
Ingham then said that Phillips had "lost the plot", to which he replied: "I may have lost the plot but i have at least maintained my manners."
It all got a bit too much for Phillips as he announced he had withdrawn from a debate at the PRCA as a result of the Twitter row. Ingham then stuck the knife in a bit further on the whole 'is PR dead?' issue:
Not wanting to lose face, Phillips suggested the two take part in a head-to-head debate on the issue, and Ingham was raring to go.
But to make things more interesting, Phillips suggested a wager with fairly high stakes:
.@citizenrobert cool. And if you lose, you repay all the Edelman money you were paid. Sounds good— Francis Ingham (@PRCAIngham) March 19, 2015
Both parties were clearly keen to have the last word, and after Ingham confirmed that he had indeed read Phillips' book, the heated exchange seemed to shut down.
The industry waits with bated breath for the two to take the spat off Twitter and deliver a public debate as promised. Watch this space.