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The big news from John McDonnell’s speech to the Labour party conference was that there was no news. Both of the shadow chancellor’s significant announcements — a £10-an-hour national living wage and £500bn extra investment — were just reiterations of previously announced policies. 

There were hints at a fuller economic agenda: a new tax avoidance unit at HM Revenue & Customs, a “renaissance” in worker ownership of companies and a greater focus on taxing wealth. Yet Mr McDonnell’s team has chosen to talk up the living wage — which was, in fact, his first policy declaration as shadow chancellor last September.

The same goes for the £500bn investment package, which Mr McDonnell announced during this summer’s leadership contest. Troublingly, there was no detail on where this money will come from. This sat oddly with his opening attacks on the Conservatives for their failure to cut the deficit.

Without a lack of detail, one has to assume that the shadow chancellor would borrow this huge sum of money — the equivalent of 10 High Speed 2 rail schemes — which would further increase the deficit. Or, it could be funded through taxation. Chris Leslie, Mr McDonnell’s predecessor, has said it would require the doubling of income tax, National Insurance, council tax and VAT. It was this sort of unfunded commitment that cost Labour so dearly in the last general election.

Brexit is surprisingly absent from this year’s Labour conference, given that it is the greatest domestic and foreign policy challenge facing Britain. Mr McDonnell did say one of his red lines in the negotiations is to “preserve access to the single market”, which is a meaningless trope also used by the Conservatives. All countries in the world have “access” to the single market — it is at what cost that matters. Does he mean a free-trade deal? Or signing up as a member, in some sort of European Economic Area-style agreement?

Mr McDonnell’s speech was well-received in the hall, as he told activists exactly what they wanted to hear. Labour will spend more, raise wages, crack down on the business practices of the Philip Greens and Mike Ashleys of this world and lead a manufacturing renaissance. These things may be possible in some form but they would come at a price. Politics is about balancing the costs and making difficult decisions. It is what politicians do when they enter government.

If, and that is a big if given the state of the opinion polls, Mr McDonnell did become the UK’s chancellor, he would soon find himself in the difficult position of having promised the earth to his party and being unable to deliver it all. And it is that kind of betrayal by past Labour leaders that led to Jeremy Corbyn’s leadership victory in the first place.

We are gradually learning more about what this new Labour party would like to do — it is radical but too much is easy, stump speech rhetoric. It is what Mr Corbyn and Mr McDonnell are used to, after all.

sebastian.payne@ft.com

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