It has been clear for some time that the Murdoch press, so assiduously courted by New Labour, will throw its weight behind the Conservatives at the next election.
The Sun and the Times's support for the Tories in last month's European elections and their endorsement of Boris Johnson as London mayor last year suggests that both are preparing to abandon Labour at the general election for the first time since 1992.
Andrew Neil, the former editor of the Sunday Times, who worked alongside Rupert Murdoch for many years, has argued that the government's more redistributive approach means there is "no doubt" that News International's titles will endorse the Conservatives.
In addition, the Daily Telegraph's Christopher Hope recently reported that the fierce criticism of former News of the World editor Andy Coulson by the Guardian over the phone-hacking scandal had persuaded Murdoch to back Coulson's new boss, David Cameron, at the next election.
The News Corporation head and his ideological guru, Irwin Stelzer, were initially sceptical of Cameron and attracted to Gordon Brown. Both were impressed by Brown's intellect, his work ethic and his religious commitment.
Murdoch, a strong opponent of monarchy and aristocracy, and nostalgic for the days when Margaret Thatcher's cabinet contained "more old Estonians than old Etonians", was also reluctant to support a man with a background as privileged as Cameron's.
As John Rentoul writes in his column today:
One thing Rupert and James (Murdoch) do seem to share is an anti-establishment mentality, a resentment against British snobbery directed against their family business: they have no affinity for someone of Cameron's background.
But as Brown's woes have multiplied such doubts appear to have been buried.
There are those who argue that newspaper endorsements are of little consequence; fewer people are reading papers and few have ever read the leaders in which endorsements are made.
Yet crucially such editorial judgements come to shape a paper's general news coverage, as embarrassing stories are amplified or diminished accordingly. The winning party can also count on a fair hearing from the relevant titles once in government. In this regard, it must be a matter of some concern to Brown's aides that Labour appears to be losing the support of much of Fleet Street .
Besides the News International titles, the Daily Telegraph and the Daily Express (which rescinded its support for New Labour in 2005) can naturally be relied upon to rally behind Cameron, while Brown's famously warm relationship with Paul Dacre, the editor of the Daily Mail, has failed to deter that paper's increasingly visceral attacks on Labour.
The Financial Times, which has backed Labour since the 1992 election, is known to be prepared to support the Tories but as the most Europhile title on Fleet Street its anger over Cameron's fierce Euroscepticism may yet prevent such a defection.
The Guardian cannot credibly endorse Labour so long as Brown remains leader, having called on the party to force him out. There is even less chance of an endorsement from the Independent, which is likely to call for a hung parliament or support the Liberal Democrats.
Only the Daily Mirror can be relied upon to offer Labour unambiguous support at the next election.
The migration of the press towards the Tories is likely to become more, not less, explicit as the election draws closer. The left may have been resigned to right-wing dominance of the media for decades but even so, the flight of the press from Labour can only further damage the morale of an increasingly desperate party.