Former editor of the Daily Mail Paul Dacre claimed that hundreds of advertisers had pulled out of the newspaper in an open letter to his successor published by the Financial Times on Saturday.
Dacre, now editor-in-chief of the Mail's parent company DMG Media, took issue with a claim that new editor Geordie Greig made in an interview also with the FT.
Greig, who took over editorship of the title a year ago, claimed in the interview that he was a "very commercial editor" and that in the past year 265 advertisers had returned to the Mail, including BP, Nationwide and TalkTalk.
In a scathing letter, Dacre, an influential editor who was at the helm of the newspaper for 26 years, appeared to challenge him.
"Admirable chap he may be, but Geordie Greig, in his 'Lunch with the FT', is as economic with the actualité [news] as your paper is in reporting matters Brexit," Dacre wrote. "He claims 265 advertisers came back to the Mail in his year as editor. In fact, far more than that number left during the same period."
The two men are said to be rivals, with Greig a Remain supporter and Dacre a staunch Brexiter. When Greig was brought in as editor, it was seen as a new era for the Mail.
In a statement, DMG Media told Campaign that over the past 12 months the Mail had grown its market share of UK press advertising.
"The advertising revenue from the 265 new advertisers in Mail newspapers more than offset the loss from those advertisers we didn’t see in the past financial year," a spokesperson said.
"We are delighted that revenue from advertising in print and digital was substantially greater than last year."