It was sparks from Labour's General Election campaign that started the fires in Parliament Square

As the dust from pulverised breeze blocks settles over Parliament Square and a battered Rolls Royce Phantom IV is carried like a wounded gladiator into the depths to be restored, questions are beginning to be asked about yesterday's protests.

"Who is to blame? How can they be punished?" will be the cry from the newspapers when they run out of photographs and personal accounts of the protests.

Well no doubt it will amuse many to see the blame placed, for a large party, with the Labour Party. But it is there that it does reside.

The grafitti sprayed onto the Treasury and the Supreme Court tells the story. "F*ck the Rich", "Make the rich pay", "Fuck your Big Society". When protesters attacked the Prince of Wales and the Duchess of Cornwall, they did so with chants of "Tory Scum" (ignorant it seems of the party-politically neutral status our Royal Family has). These are not just expressions of anarchist anger, but campaign slogans, left over from the general election. It was Labour's desperate and destructive desire to cling to power that led to one of the dirtiest fought election campaigns in years. This election was the first in nearly 100 years where a result had to be overturned due to incendiary campaign literature of a Labour party MP. That does not mean it was the most incendiary in nearly 100 years, but it is evidential of the depths that Labour was prepared to go to mobilise its wavering base.

Any Conservative on a campaign trail knows that they will be subject to angry and aggressive outbursts from radical Trotskyists. But everyone I know says that in this last election it was much worse.

This abuse stemmed directly from the centre of the Labour Party. Labour's election adverts whipped the public into an angry fury. The "Nightmare on Your Street" broadcast was the most emotive (note that it is still available for viewing on the Labour Party website). Labour fought their election on the basis of "the many against the few", telling the electorate that Tories were there to look after their millionaire friends. Hansard's record may now be seen on graffiti in our capital: "playing fields of Eton" and "Bullingdon Club" daubed in pink paint on centuries old buildings. Senior Labour members were quite happy to use the #ToryScum tag on their tweets at the last election. What did they think would happen?

We are now reaping the aftermath of Gordon Brown's desperate election strategy, where their policies could not match those of the Conservative Party and so their angry lies were forced to fill a gap. And Ed Miliband's quip at PMQ's this week about the Bullingdon Club shows that his New Direction is as weak as the last. (It is quite amazing how yesterday he managed to snatch defeat from the jaws of victory by explaining how he would be very unlikely to overturn this controversial bill!)

Now Labour clearly 'condemns any violence' but it is they who are responsible for creating the atmosphere in which any expensive car may be attacked in central London, they are responsible for turning anger and violence ('passion' in Labour speak) into the campaign tool we saw yesterday.