Two senior newspaper executives have condemned journalists’ “unbecoming” use of social media to share their opinions and exclusive content.

Will Lewis, the former boss of Dow Jones and the Wall Street Journal, and ex-Financial Times editor Lionel Barber have also spoken of their uneasiness about the “blurring” of opinions and facts in journalism.

Lewis – who recently left his role and missed out in the race to become the BBC’s next director general – said that in “this increasingly resource-constrained time… journalistic standards are inevitably slipping. And we’re beginning to see the blurring of facts and comments in a way that I think is extremely worrying and extremely challenging.”