An audacious effort by the American media executive Jeff Zucker and his Emirati backers to acquire London’s Daily Telegraph appeared to be on life support on Wednesday after the British government advanced legislation that would bar foreign state ownership of newspapers and newsmagazines.

The move by Prime Minister Rishi Sunak would torpedo Mr. Zucker’s bid in its current form, which relies heavily on financing from investment partners in the United Arab Emirates. The use of Emirati funds caused an uproar in Westminster over foreign influence in the British media, given the outsize importance of The Telegraph and its sister publication, The Spectator, to Mr. Sunak’s Conservative Party.

Mr. Zucker’s media venture company, RedBird IMI, can now try to salvage its bid for the publications by finding new investors and diluting the Emiratis’ majority stake to a level allowed under the government’s proposed rules. His representatives had no immediate comment on Wednesday.

The attempt by Mr. Zucker, a former president of CNN, to reinvent himself as an unlikely news mogul in Britain shocked many of the country’s leading media players, including Rupert Murdoch, who had considered acquiring The Telegraph for themselves after the paper went up for auction last year.

Prominent Tories, including the broadcaster Andrew Neil and Fraser Nelson, editor of The Spectator, pounced on Mr. Zucker’s reliance on Emirati funds, turning the transaction into a political flashpoint over foreign influence on British institutions and galvanizing opposition from Conservative Party lawmakers.

The deal was already under review by British regulators. On Wednesday, in the House of Lords, Stephen Parkinson, a minister for culture communications and creative industries, promised to bring forward an amendment to legislation that would prevent foreign state ownership of news publications. The law is expected to pass Parliament, where the Tories have a healthy majority.