Jeremy Corbyn has attacked the sale of the i paper to the publisher of the Daily Mail, saying that "two billionaire press barons" now own half of the UK's 10 biggest-selling dailies.
DMGT agreed to buy the i on Friday for £49.6m from JPI Media - more than double its price tag just three years ago. The purchase ended months of speculation over bidders for the paper, which was considered to be the crown jewel in JPI’s stable.
The Labour leader tweeted: "Remember this when they attack Labour's plan to make the super-rich pay their fair share."
However, Paul Zwillenberg, DMGT chief executive, said that the editorial independence of the i would be maintained.
"I want to make absolutely clear that we will ensure that the editorial independence of the i is preserved. Its readers value its distinctive style and politically neutral approach and we are committed to maintaining that," he said.
Throughout his career, the Labour leader has been a vocal critic of media moguls such as Rupert Murdoch, who owns the Times and the Sun, and Lord Rothermere, whose stable includes the Daily Mail.
Mr Corbyn launched his general election campaign last month by issuing a blistering tirade against the "privileged few" who benefit from a "corrupt system", in which he cited Mr Murdoch as a person he wanted to "go after".
In an interview with the i in 2017, Mr Corbyn said that he was a loyal reader of the paper and bought it every morning. "I like it because it has informed, quick-read articles," he said.
Lord Rothermere, DMGT’s chairman, said: “We are delighted to welcome the i to our stable of media brands. It is a highly respected publication with a loyal and engaged readership. We are committed to preserving its distinctive, high quality and politically independent editorial style.
“The acquisition of the i is both strategically and financially compelling for DMGT and there is scope for potential synergies in the future, notably from DMG media’s existing infrastructure and in advertising sales.”
DMGT said that it expected the JPI deal to be reviewed by competition regulators.
JPI also owns the Yorkshire Post and the Scotsman and was formed last year after a private equity-led rescue for Johnston Press.
The announcement followed Reach, the publisher of the Daily Mirror, saying that it had pulled out of the race to buy JPI titles.
Reach said trading was steady in the five months to November as growth in digital revenues slightly offset a fall in print.
Total revenues fell 4.4pc, better than the 6.6pc fall for the same period last year. Shares jumped 15pc to 96p.
The i sells about 170,000 copies on weekdays and more than 190,000 copies on Saturday, while its website has some 300,000 daily unique users.