Prime Minister Theresa May's hopes of clinging on to power have taken a further hit after the UK's biggest selling newspaper called on her to stand down.

The Sun, owned by Rupert Murdoch, published a savage attack on her premiership.

It will fuel talk of a Tory coup, as well as speculation the media mogul has struck a deal with her potential successors.

In an editorial printed on the front page of Monday's edition, The Sun called on Mrs May to announce she will stand down as soon as her Brexit deal is approved and Britain is out of the European Union.

The newspaper said it was issuing the plea with regret, "­having supported her since before she became Prime Minister", but insisting that she has "lost the backing of much of the country and now her party".

The editorial reads: "Her deal has only one, slim chance of achieving a majority in the ­Commons. That is if she pledges ­immediately to resign and set in motion the election of her successor as Tory leader and PM after we leave the EU on the new deadline of May 22.

"If she does so, Tory Brexiteers and the DUP must back the deal. Because if it fails again this week, we are heading for a much softer Brexit – or none.

"That will be a catastrophe for the country, the Tories and Parliament."

The Sun also hailed Mrs May as "a dedicated public servant with an unshakeable sense of duty, who in 2016 took on the greatest challenge of any PM since World War Two."

It added: "She has stuck to it through thick and thin, showing remarkable resilience in the face of repeated humiliations, rebellions and a relentless barrage of vitriol from almost all-comers.

"Unlike so many, she has determinedly respected the will of the Leave majority. The very concept of democracy has been degraded in many other countries, yet she has ­resolutely defended ours.

"She must now take the next principled step – and show she is not just another craven politician determined to cling to power."