Rupert Murdoch’s Sun on Sunday newspaper said Prime Minister David Cameron had failed to get a proper deal for Britain from other European Union leaders and was now on the wrong side of history by supporting membership.
The open opposition of Britain’s most popular newspaper is a blow for Cameron who has said he will fight for membership in a referendum he has called for June 23.
“Whatever we think of David Cameron’s deal and the case for remaining in the EU, we don’t doubt his sincerity. We just think he’s wrong,” the Sun on Sunday said in an editorial.
“His failure to get a worthwhile deal means that he’s now on the wrong side of history,” the newspaper said in an edition which also ran an article by Cameron arguing for membership.
Cameron said that Sun on Sunday readers would be “key voters in one of the biggest decisions of our lifetimes”.
Murdoch opened up the possibility that some of his newspapers could oppose membership on Saturday when he congratulated one of Cameron’s closest political allies, Justice Secretary Michael Gove, for opposing Cameron on the EU.
“If we vote to stay after making such a fuss about leaving, the rest of the EU will conclude that although we moan a lot, when push comes to shove we’ve not got the fight to actually do anything,” the newspaper said.
“Yes, the Leave campaign may be chaotic, with petty arguments between the different groups … But that doesn’t mean the fundamental argument is wrong.”
Meanwhile Cameron on Sunday implored Boris Johnson not to join the campaign for a British exit from the European Union as the charismatic London mayor prepares to declare his stance on membership.
Johnson, who has charmed some voters with a buffoonish persona that masks fierce ambition to succeed Cameron, has so far been silent though British media are speculating that he 51-year-old mayor will join the campaign to leave the EU.
Cameron cautioned Johnson against joining with opponents of the EU such as UK Independence Party chief Nigel Farage and maverick campaigner George Galloway.
“The prospect of linking arms with Nigel Farage and George Galloway and taking a leap into the dark is the wrong step for our country and if Boris, and if others, really care about being able to get things done in our world then the EU is one of the ways in which we get them done,” Cameron said.
“I would say to Boris what I say to everybody else, which is that we will be safer, we will be stronger, we will be better off inside the EU,” Cameron told the BBC.
The rumpled mayor is due to publish his views on Britain’s EU membership at 2200 GMT on Sunday.
An Ipsos MORI poll showed Johnson, 51, is second only to Cameron when it comes to swaying public opinion on Europe. One in three voters said Johnson would be important in helping them decide which way to vote, the poll showed.
Johnson, instantly recognisable thanks to his riotous platinum-blond hair, has asked Cameron to give additional guarantees that the British Parliament is sovereign over EU laws, though it is unclear how Cameron will do that.
“We are going to set out in the coming days proposals… to make clear that British parliament is sovereign,” Cameron told the BBC but refused to give further details.