When Ed Balls was first elected to represent the adjacent seat to mine, I became his parliamentary mentor. My job was to explain to him the mysteries of the Commons: a kind of “Strictly Come Governing”. But my role didn’t last long; Ed is a quick learner - as the nation saw when he put on his dancing shoes.

Sadly, I feel it necessary to mark him down on his latest performance at Glastonbury. Ed reportedly said: "I like this manifesto but I don’t think it’s the right one to take us into the next election" and that Labour in office would have to tax everyone, not just the rich.

He continued: "The right thing for Jeremy Corbyn and John McDonnell to do is to understand why they lost. In the end you can’t be an outsider and be the Prime Minister. Jeremy has to become a trusted insider…"

I’m not sure Ed has learnt from his 2015 defeat. But Labour certainly has. Our politics and economics have moved on since the New Labour years. And there can be no turning back. The country knows that we need radical change. How else can you explain the fluidity of party politics and the extraordinary growth of our membership, but also the Brexit vote and the Scottish referendum result?

There is a profound discontent in the country - a mood of insurgency. A party of the left cannot be the "insider" party of the British Establishment whilst simultaneously drawing its support from middle and lower earners - the very people who have borne the burden of austerity.

We should campaign as we mean to govern: as insurgents against a rigged system. We cannot campaign as "outsiders" and then govern as "insiders". As an opposition we want to mobilise the many. As a government we would transform the country by opening up the closed circle which rules Britain in its own interest.

Can this be achieved economically? Here we come to the second part of Ed Balls’ argument. He appears to reject the central tenet of Labour’s offer to the nation. This is that there is sufficient wealth in the country to finance our public services and to create social justice.

There are several parts to Labour’s case. First, the country has tried austerity to the point of destruction. For example, most people were aghast to learn we’d lost 20,000 police officers. This feeling was compounded when there were terror incidents on our streets. This week’s Social Attitudes Survey showed a major shift against austerity. This was illustrated by a staggering 80 per cent of potential Tory switchers wanting to end the pernicious public sector pay cap.

When it comes to rejecting austerity, more people are dancing to Labour’s tune. Our manifesto showed that it was possible to develop a fully costed set of proposals which begin to restore the public services to the levels which a civilised country ought to possess. The naysayers who want to continue to raise the taxes of the majority are simply wrong. Labour would protect the 95 per cent but take more from the wealthiest 5 per cent, the larger corporations as well as those who so arrange their personal or corporate situation as to avoid paying tax.

In addition, we would kickstart economic growth, which would help to provide the revenues to fund our services. Because growth won’t happen inside a fiscal straitjacket of public service cuts.

On the subject of redistribution, obviously it is an objective of any party committed to social justice to bring about a more equal society. But this also has a beneficial economic effect because lower income earners are more likely to spend their income locally than wealthier groups. This in itself will help to produce economic growth and to finance the public services.

There is also a regional dimension to Labour’s economic case. We have a lopsided economy. When the South East overheats, many other regions are still not fully stretched. A more equitable country with regionalised investment banks could stimulate the economy outside of the South East. The whole nation would be better off.

Public ownership of natural monopolies like the railways is not only a patriotic response to the sale of our assets to overseas governments. It is also popular. But in this context, we shouldn’t forget that the surpluses produced by these enterprises would then help the Treasury, rather than lining the pockets of already wealthy shareholders.

Rather than looking back nostalgically on an economic settlement which went into crisis in 2008, and has been staggering on ever since, it is time to move on. Labour’s leadership represents a decisive break with these failed years and offers new hope for the future. The single most important action which Labour’s leading members (past and present) can do is to unite behind that programme.

Unity in the face of a government which has lost the moral authority to govern, exercising power in the interests of a narrow political faction, will surely bring us closer to a Labour government. When we win, the same unity will help set the country on a fresh path.

Ed Balls may have missed his steps on this particular dance. But I hope he’ll embrace the change. Its time to drop Gangnam style, follow the public mood and learn the steps to the Corbyn Jive. If he does, he’ll get a 10 from me. And as a united party, Labour will get a Number 10 from the public.