Labour's row over the mansion tax is not a sign of 'civil war' within the party but a sign Labour are finally waking up to what devolution means for British politics.
The Scottish parliament and the London mayoralty were set up by Tony Blair with the confidence that they would be filled with loyal commissars who would remain eternally loyal to the Labour party.
Voters had other ideas. In London, a once reliably left-leaning city elected staunchly independent non-Labour mayors three times out of four elections.
Meanwhile, Holyrood oversaw the rise of Scottish nationalism which now threatens to cost Labour the next general election.
Signs of the agony these developments have caused were seen in yesterday's row over the party's proposed new mansion tax. The row was sparked by comments from Scottish Labour's new leader Jim Murphy that he would fund 1000 new nurses from the new tax "95% [of which] will be levied in the South East of UK".
These comments caused an immediate outcry from London mayor Boris Johnson who described Labour's policy as "vindictive" and an attack on the capital. In a country where 'London' and 'Westminster' are increasingly used as insults, Johnson's comments could not have been more helpful to Labour's new Scottish leader.
Labour's Mansion Tax will pay for 1000 extra Scottish nurses. Boris says that's "vindictive". We say it's fair pic.twitter.com/uely33tkXW— Kezia Dugdale (@kdugdalemsp) January 7, 2015
Yet it was the reaction from Labour's own ranks which caused the biggest headlines. Murphy's comments were attacked by not just one but three potential Labour mayoral candidates.
Tessa Jowell, Diane Abbott and David Lammy attacked Murphy's comments which suggested he wanted to "siphon off" money from London and treat it like "a cash cow".
The row culminated in a remarkable on-air confrontation between Murphy and Abbott on the World at One, in which Abbott accused Murphy or trying to "expropriate" London properties while Murphy all but told Abbott to put a cork in it.
The row coincided with the release of new comments by another potential mayoral candidate (and staunch Miliband loyalist) Sadiq Khan in which he warned his mayoral rivals that the party would "not forgive" those who let their ambitions get in the way of a Labour general election victory.
These comments were echoed in a piece by Labourlist editor Mark Ferguson who accused Khan's rivals of "doing the Tory press office's job for them" on the mansion tax and warned that "I'll find it very hard to back a London mayoral candidate who puts their ambition ahead of electing a Labour government."
Yet for all the warnings that these internal divisions will dent their chances, Labourlist's own surveys show that support for the candidates opposing the mansion tax has actually gone up in recent months, while support for Labour's only candidate backing the tax (Khan) has gone down.
What both Khan and Ferguson have yet to grasp is that rather than being a weakness, independence from the party leadership is actually hugely important when it comes to devolved politics.
In four mayoral elections, Londoners have always elected a candidate seen as independent from their parties, while more loyalist candidates have gone the way of Frank Dobson.
What both Boris Johnson and Ken Livingstone before him understood is that criticism of your own party's policies does not necessarily cost votes, but can actually secure them. The nature of devolved politics is that voters want to see their candidates speaking up for the interests of their region, not just the interests of their own party. And if that means causing the occasional row with their party leader, all the better. Where Ken Livingstone once led, Jim Murphy is now following.
This new type of politics can sometimes be very difficult to accept. In London, Khan's rivals for City Hall have accused him of failing to understand how mayoral politics works.
"It comes from a view within the party that we'll win the mayoralty regardless and so can afford to only think about it after May," one ally of David Lammy told Politics.co.uk
"David's view is that London can't be taken for granted as an afterthought in that way."
Opposition to the mansion tax may seem counterintuitive, especially when it comes from someone on the left like Diane Abbott, but it is actually political common sense. It's not that new taxes and charges on the wealthy can't ever be pursued. The congestion charge was implemented against significant opposition.
But the difference with the congestion charge, is that the revenues were raised in order to benefit Londoners. Most of the benefit from the mansion tax will go elsewhere. In a pre-devolution era this would have been much easier to accept, but not now.
In the post-devolution era, any candidate standing on a ticket to raise taxes in their area in order to pay for things outside their area, will meet with great difficulty. It is this principle rather than the principle of taxing properties that has caused the opposition within London Labour.
The mansion tax row is not really about mansions or nurses at all. It is about devolved politics. Labour devolved political power to the regions. Rows like yesterday are the inevitable result of that.
Far from damaging Labour's chances, such rows have the potential to actually help the party both in Scotland and in London. This is the new reality of a devolved Britain. Rather than attacking this new style of politics, Labour should be embracing it.