So, despite the vehement campaign against him  by Britain's biggest-selling daily paper, this has turned into a good week for Gordon Brown. It may have been unthinkable for Labour not to win last night's by-election in Glasgow North-East , a seat it has held for 74 years, but few expected the party to triumph by the margin it did.
The by-election victory was the third piece of good news Brown has had this week. First, a Times/Populus poll  on Tuesday demonstrated that a hung parliament remains a distinct possibility at the next election. The Conservatives' lead of 10 points would translate into a Commons majority of only two.
Second, a PoliticsHome poll  revealed that 65 per cent of voters believe the Sun's reporting of Brown's letter to Jacqui Janes became an "inappropriate attack", and that almost half of the electorate is now more inclined to defend the Prime Minister.
Perhaps buoyed by these figures and the by-election success, Brown gave the most articulate and fluid performance I've heard from him for weeks on the Today programme this morning .
Professor John Curtice  noted the key to Labour's success last night when he observed: "They fought as the opposition to the SNP." But he provided a sober dose of reality when he pointed out: "The recipe for success in Glasgow is not one that can be repeated in England and Wales."
Lord Mandelson and Harriet Harman have attempted to mount an insurgent campaign by consistently referring to Labour as the "underdog". But in England at least, the party continues to be seen as the establishment.
In order to change this, Labour must gamble on a referendum on electoral reform before the next election. The Conservatives remain wedded to the unjust first-past-the-post system. Perhaps on this issue alone, David Cameron would be left defending the status quo.