The Daily Mail has backed Theresa May’s plans for a soft Brexit and described Conservative MPs plotting to oust the prime minister during the negotiations with the EU as “traitors”.

Geordie Greig, a former remain supporter who took over as editor from the arch-Brexiter Paul Dacre last week, appears to be shifting the newspaper’s editorial tone towards support for Downing Street’s Chequers plan.

An editorial in the Mail on Thursday strongly criticised discussions by Brexit-supporting Tory MPs about May’s future as the “latest manifestation of the party’s apparent death wish”.

On a separate page, Andrew Pierce’s reported account of the meeting was headlined “One by one, traitors put the knife into Theresa”.

Facebook Twitter Pinterest The editorial from the 13 September 2018 edition of the Daily Mail. Photograph: Daily Mail/Associated Newspapers

The editorial said: “The Mail has never made a secret of its reservations over aspects of the Chequers compromise. But as the talks with Brussels enter their final stages, the truth is this is the only blueprint for Brexit on the table.

“The perception grows that Conservatives are too busy fighting each other to attend to the issues that affect millions – such as the surge in violent crime, recurrent train delays, long waits for GP appointments or the near impossibility of home ownership for most young families.

“What possible good can Tory Brexiteers hope to serve, at this hugely sensitive moment in the talks, by wielding their daggers against her [May]? It is not as if they have the numbers to bring her down. Let alone do they have a coherent alternative plan for Brexit – nor, indeed, an obvious candidate to replace her, capable of uniting a divided party.”

As editor, Dacre was supportive of May but focused relentlessly on Brexit, and he has publicly warned against softening the paper’s line on leaving the EU.

The extent to which the Mail’s editorials directly influence the views of the 1.3 million people who buy it every day is a matter of debate, but the newspaper’s print edition remains influential within government and among broadcasters, setting the tone of the political debate.

The initial editions of the Mail under Greig appear to suggest a more nuanced editorial line, where a soft Brexit is a price worth paying to keep Jeremy Corbyn, the Labour leader, out of No 10. The shift is in line with what Daily Mail insiders told the Guardian last week.