My regular column is available to subscribers on www.thetimes.co.uk This is an excerpt. Not to be reproduced without permission.

This is a great time to be leader of the opposition and to be shadow chancellor. The polls are going well and the cares of office are still some way away. It is a particularly good time for Sir Keir Starmer and Rachel Reeves. They won the economic battle of the party conference season comfortably, helped by some own goals from the government.

Rishi Sunak’s effort in Manchester, in which he cancelled the northern leg of HS2, turned into even more of a train wreck when it emerged that the list of alternative infrastructure projects on which he suggested the money saved would be spent was merely “illustrative”.

As for Jeremy Hunt, he had to resort to tweeting that Reeves had not used the word inflation in her speech. She had, of course, talked about rising prices and the cost-of-living crisis. Wordfinder tools should be banned in politics. They just make those who use them look silly.

As it was, Starmer and Reeves were able to plant their tanks firmly in traditional Tory territory. While the prime minister could not use the expression “iron clad” with reference to fiscal discipline with a straight face, they were able to do so.

Labour’s economic transformation is extraordinary in comparison with where the party was at the time of the December 2019 election, when Jeremy Corbyn was leader and John McDonnell shadow chancellor. AS a former Bank of England governor, Mark Carney was unwise to endorse Reeves as chancellor, but he was only reflecting what many people in business think.

These are, as I say, golden times for Starmer and Reeves but it is only fair to ask some questions. In his speech, Starmer set out Labour’s four-step programme for economic regeneration.

Step one is a “national wealth fund”, which will be “ready to invest in the critical infrastructure we need. The battery gigafactories, the clean British steel, the ports that can finally handle large industrial parts. More growth, more demand, more jobs.”

This is a curiosity. National wealth funds are normally the product of healthy public finances which result from a resource windfall. That is why Norway has one, currently valued at well over £1 trillion, which is a lot for an economy which is less than a fifth of the size of the UK.

I may have missed a detailed prospectus for Labour’s national wealth fund but, according to a speech by Reeves last year, it will be set up with £8 billion of government capital, with the hope that the private sector will come in. There are no budget surpluses to be invested in it and on the face of it, this is a very modest proposal. You might get a few clean steel plants and one or two more gigafactories, but not much else.

Steps two and three were fairly workaday pledges, to provide the stability that “researchers, investors and innovators” need, and to provide “a new direction for skills” with what Labour calls technical excellence colleges.

Step four, “Great British Energy” is more interesting, and raises more questions. The “Great British” branding is a tarnished, the government’s proposed Great British Railways having been shunted into the sidelines.

Great British Energy would, according to Labour, be “a new home-grown, publicly-owned champion in clean energy generation – to build jobs and supply chains here at home” based in Scotland. The party is better at talking about the proposed benefits of leading “the world with cheap and clean power”, knocking a claimed £1,400 of annual household energy bills and £53 billion off business energy costs than explaining in detail how it would work.

It is a strong nod towards what Reeves has called “securonomics” and Joe Biden’s Inflation Reduction Act in America. Polling suggests most people would prefer energy supply to be publicly owned, as it is in some other countries in Europe.
Then it gets tricky. The question of how Great British Energy would interact with existing private sector energy providers is an interesting one. The new nationalised entity would, Labour has said, make “strategic investment that companies shy away from”, in other words the risker ones. That could pay dividends but equally it could be a great way of losing large sums of public money. Labour has changed, but this smacks of the failed strategy of picking winners of the past.

Finally, the pledge to significantly increase housebuilding was a highlight of Labour’s economic offering. I would wager a significant sum, however, that we will not see 1.5 million new homes built in England over the first five years of a Labour government.

On the most generous measure of housing supply, net additional dwellings (which includes conversions from other uses) the figure has averaged less than 190,000 a year since 2010. On the conventional measure, housing completions, it has been even lower, just under 142,000.

The Labour leader has admitted that it will take time to build up to the annual level of housebuilding needed to get to the 1.5 million target, implying that by the end of a Labour parliament, well over 300,000 new homes will be being built annually. That has not happened since 1969, and when it did, more than 40 per cent of new homes were built by councils.

Tinkering around with the grey edges of the green belt, which is no bad thing, and “bulldozing” through planning restrictions, which is a good thing, will not deliver the kind of boost to housebuilding the Labour leadership wants. New housebuilding for private buyers in England has never exceeded 200,000 a year, according to official statistics.

In the end, Labour’s ambitions come down to the oldest question in economic policy: where will the money come from? As a new assessment from Oxford Economics points out, Labour’s plans will run-up against the fiscal realities of what looks like a grim inheritance should the party win next year’s election. That “iron clad” fiscal discipline will have to start from a difficult position.

As it points out: “The UK's Office of Budget Responsibility's latest fiscal projections are based on policy being tightened significantly after the election … Current plans imply large departmental spending cuts in real terms. Given its relatively modest plans for raising tax receipts, it's hard to see how Labour could reduce these spending cuts, increase NHS spending, and implement its green prosperity plan.”

It is good the Labour has ambitions, but Starmer and Reeves should make the most of this time in the political calendar. The realities, assuming they get into government, will be much harder.