A little over a decade ago Dovid Efune was juggling editorship of the New York-based Jewish publication the Algemeiner Journal while also handling publicity for Israel’s first world boxing champion.

Now, the owner of the New York Sun is the leading contender to buy the Daily and Sunday Telegraph, but his fighting talk about the situation in the Middle East has sparked alarm among staff about the editorial influence and impartiality of their potential new owner.

As the conflict intensified this week, with Iran launching missiles into Israel, the British-born Efune – who has described himself in the past as a “conspicuous Jew” – upped his typically strident views on social media.

In a series of posts on X, formerly known as Twitter, he said Israel would “decapitate” Iran’s leadership with “targeted strikes and close quarter assassinations … I’d expect the Ayatollah himself would be in the cross-hairs”.

Last year, Efune gave a speech at a gala in New York held by the Algemeiner, where he now holds the title of honorary chairman, where he told attenders that when it comes to the Israel-Hamas conflict there is a need to “fight with every report and headline”.

Telegraph staff had railed against the potential editorial ramifications of being taken over by a consortium led by the GB News co-owner Sir Paul Marshall, which did not submit a second-round bid for the titles, and now they are alarmed by the political bent of the new frontrunner.

“We are out of the frying pan into the fire,” said one newsroom insider at the Telegraph. “His tweets over the last few days are not the behaviour you want to see from a newspaper proprietor. It compromises everybody by association.”

Alice Enders, director of research at Enders Analysis, said that if Efune does acquire the Telegraph titles he will come under scrutiny from UK regulators, but his views on social media will not necessarily be a major factor.

“The regulator will be looking at the structure of the deal and whether the owner has a good track record as a publisher in terms of things like appointing editors that are in charge and internal plurality,” she said. “Media owners can have views and tweet them, and the editorial direction of a newspaper is another matter.”

Efune, 39, was born in Manchester and has said he did not attend traditional schools beyond the age of 11, instead attending Jewish academies to study the Torah (the first five books of the Bible) and rabbinic traditions.

While Efune has built his media career in the US, his family has historical ties with the British commercial and political establishment. His grandfather, Peter Kalms, was the finance director and deputy chairman of Dixons, the electronic retailer founded by the Kalms family.

Lord Kalms, a cousin of Efune’s grandfather, was chairman of the company for more than 60 years and was treasurer of the Conservative party between 2001 and 2003. Kalms, who is on the advisory board of United Against Nuclear Iran, which is chaired by the former Florida governor Jeb Bush, was expelled from the party in 2009 after voting for Ukip.

Efune first came to prominence in the media sector when he was appointed editor-in-chief of the Algemeiner in 2008, after meeting Gershon Jacobson, the founder of the 52-year-old publication, through his studies.

He was elevated to editor by Jacobson’s sons, following the death of their father, and Efune switched the title from a Yiddish-language to an English-language product.

In 2021, Efune took control of the assets of the former print publication the New York Sun in a deal with its founding editor, Seth Lipsky. Formerly a New York newspaper published from 1833 to 1950, it returned to newsstands under Lipsky from 2002 to 2008, establishing a politically conservative tone.

Efune, who lives in New York, struck a cash-and-shares deal for an undisclosed sum and relaunched it as a digital-only title, which counts the former Telegraph proprietor Conrad Black as a columnist.

When the deal was announced, Efune praised the publication for “practicing precisely the form of journalism that’s so lacking in today’s media environment: values-based, principled and constitutionalist”.

In February, Efune published a “letter from the publisher” in the NY Sun marking the title’s second anniversary of returning to daily publishing.

Efune, who has encouraged X owner Elon Musk multiple times to try reading the NY Sun, wrote that there has been a “realignment of priorities” at many of America’s “most-storied publishers”, saying that “they have come to serve other masters” – such as advertisers.

“There have been newspapers acquired as status symbols by billionaires and deployed as ideological playthings,” he said. “Others have been designed or repurposed as government organs. The Telegraph in Britain, a fine newspaper, is now at risk of being swallowed up by the United Arab Emirates.”

At the time of his editorial piece, RedBird IMI – the consortium backed by Sheikh Mansour bin Zayed al-Nahyan, the vice-president of the United Arab Emirates and the owner of Manchester City football club and the US investment firm RedBird Capital Partners – had effective control of the Telegraph following a £600m deal with the Barclay family.

RedBird IMI was forced to put the Spectator and Telegraph titles back up for sale in the spring after the British government published legislation to block foreign states or associated individuals from owning newspaper assets in the UK.

Efune has brought on board the boutique investment bank LionTree, founded by Aryeh Bourkoff in 2012, to put together the backing for a £500m bid for Telegraph Media Group.

LionTree has worked on deals including the 2019 merger of CBS and Viacom, the owner of Channel 5 now known as Paramount, the acquisition of the subscription-based sports site the Athletic by the New York Times, and Amazon’s $8.5bn deal to buy Hollywood studio MGM.

“The bid has come out of the blue and he is not well known here,” said Enders. “I think one of the things people seem to be doing is identifying the Telegraph bid with the person rather than the venture. We still don’t know the structure of this deal.”

Advisers for RedBirdIMI are hopeful of announcing the preferred bid for the Telegraph next week, or move to a “best and final offer” scenario if there is more than one equally competitive offer.

Efune’s career to date includes a period acting as publicist for the Israeli boxer Yuri Foreman, a former World Boxing Association super welterweight champion. Now he will be hoping to deliver the knockout bid for control of one of the UK’s most politically influential newspapers.