You do not have to like the UK Labour party’s economic policies to be taken aback by their sweep. To hear John McDonnell at the Labour conference is to believe absolutely that he has a transforming vision.

You do not have to abandon your critical faculties to appreciate the power and reach of his ambitions. Britain’s shadow chancellor has seen an enfeebled Conservative party all but give up making the case for the free market and is pressing home his advantage. With plans to force workers on to boards, for a 10 per cent share dilution of large companies with the proceeds shared between workers and government, and for an extensive programme of renationalisation, Labour is offering an uncompromising agenda, one that embeds his notion of workplace democracy across the business landscape.

The policies — as my teachers use to say — could use some work. The equity redistribution plan boasts some elephantine holes on the practicalities. How will it apply to UK subsidiaries of foreign companies? Or to non-listed businesses? If only a percentage of the equity will end up in workers’ pockets, is this not in fact a new business tax dressed up as employee benefits?

It is also easy to glean the deeper agenda of entrenching trade unions as political spearheads in every section of the economy. But these ideas — with the promise of up to £500 for employees — will strike a chord with many voters, who see executives enriching themselves as life gets worse for workers. There is a mood in the country for rebalancing an industrial settlement that has moved too far against workers. Mr McDonnell has grasped the climate and is moulding it to his political views.

Critics will talk of the adverse impact on investment and growth. But Labour is ready to argue that out and — as the failure of “project fear” in the EU referendum shows — voters may respond to the emotional appeal of a fairer share.

On the most profound political issue of the day, Labour’s plan is to say as little as possible

It is striking therefore to compare the confidence and ambition of Mr McDonnell’s agenda — and I use those words neutrally — with the breathtaking insincerity and cowardice of Labour’s stance on Brexit.

Entering this conference, delegates must walk past a fairly convincing lookalike of the former foreign secretary Boris Johnson. It is apposite. For the cynicism displayed by the Labour leadership over Brexit is almost Johnsonian.

Members and voters have started to notice that its position on Brexit is — shall we say — somewhat tactical. Labour wants a general election and it will vote down any deal Theresa May brings back from Brussels in order to facilitate that. But this is where the honesty ends. Officially it will oppose any deal that does not meet six unmeetable tests. These include retaining all the benefits of the single market while stopping free movement of people. Why didn’t the Tories think of that?

This is the limit of Labour’s policy. On the most profound political issue of the day, its plan is to say as little as possible.

Now, under immense pressure from its activists, it has agreed to a conference debate on a second referendum while giving itself enough wriggle room to ensure that any motion agreed permits everything while requiring nothing. Even as they were conceding the possibility of a second referendum, party leaders were making clear that such a vote could not include the option to remain in the EU.

You cannot exactly blame Jeremy Corbyn for ducking and diving on Brexit. The opposition leader has played a shrewd game; his only strategy being to destabilise the government in the hope that it falls before the cracks in his own party become too obvious to voters.

Labour has no need or desire to own Brexit. Voters may be irritated but they will blame only the Tories for what follows. Mr Corbyn’s strategists also know that a significant minority of its voters support Brexit and are vulnerable to Tory targeting, especially in the north. The party’s approach may be cynical; amoral even. But it is not foolish.

There is also the chance that some in the party are not unhappy at the prospect of a Brexit-induced crisis of capitalism. Did Mr McDonnell give the game away in his peroration? “The greater the mess we inherit, the more radical we have to be. The greater the need for change, the greater the opportunity . . .”

Them’s fighting words. Yet there is a short-sightedness to Labour’s fatalism, for Brexit is the sea in which economic policy must float. For all the bravado, the greater the economic turmoil that follows a bad Brexit, the more difficult it will be for Labour to force through changes that make Britain a less attractive prospect for investment. And the markets have a way of reaching a different conclusion about the credibility of any government’s economic plans.

robert.shrimsley@ft.com