How upset Labour are depends on where your bullshit detector points between Harriet Harman's, rather tepid "we're all angry but we won't be bullied" rant; rumours that Brown berated Sun execs with a four-letter tirade and Labour spin that it doesn't really matter.
Look, Labour, or rather Tony Blair, would not have courted Rupert Murdoch the way they did if it didn't matter. But perhaps they were taking the Sun Tzu approach of keeping your friends close but your enemies closer. Either way, after the paper's declaration in 1992 that "It's the Sun Wot Won It" when John Major defeated Neil Kinnock with a little help from his friends at Wapping who exhorted the last person to leave Britain if Kinnock won to turn off the lights.
But that was 17 years ago, when the internet was just being born and things have changed in the way people relate to newspapers.
Not that newspapers had as much impact as they would have you believe if you take account of this study which states that while papers might hold some sway over individuals, it would be wrong to overstate their influence on the outcome of elections.
A view echoed by Alistair Campbell, who writes on his blog: "...people will make their own minds up. What a daily paper urges them to do will figure marginally if at all in that judgement, and provided Labour continues to defend the record, take the fight to the Tories, and set out the forward policy agenda with clarity and vigour, the battle ahead can still be won."
My point is that back in 1992 The Sun might get away with claiming its part in the Conservative victory. But now, in a political scene no longer dominated by print media, where 24-hour news and internet sources are far more likely to break political news than The Sun is, it's a brave move for a dead-tree outlet to claim as much influence as it does.
Of course, if the gamble pays off then it will no doubt run a suitably self-adulatory headline the next day. But what if they don't?
What if the economic recovery is just round the corner and its effects are felt before the next election? What if the electorate decides that on balance things are looking up and they don't want to gamble on the Tories?
The Tories will weather it of course and hope to be back next time. But for the paper that backed them and failed to get Cameron into Downing St it could be far more devastating. An unmistakable sign that the paper had been emasculated and its political influence was at an end.