The British are giving up on owning things. For a generation there has been an extraordinary selling-off of public and private assets to all comers. It is not just the privatisation of former public assets, with the government last week congratulating itself on the sale of its stake in Eurostar for £750m – the latest mindless cashing in of a key public asset.

This is matched by the private sale of companies – cumulatively £440bn sold abroad over the last 10 years alone. The average Briton will now work, drink, travel, eat, drive, and use energy from assets and services supplied by foreign owners more than ever before – and in a growing and escalating deficit. Globalisation obviously means increased inflows and outflows of capital. But overseas investors are buying a great many more British companies than we are buying abroad – a ratio of more than two to one. It is not just that the control of our economic destiny moves abroad with nobody turning a hair; the associated flows of income abroad are beginning to be alarming.

It is an ownership crisis – and it should be the subject of huge national debate. But in a forthcoming Channel 4 programme Selling off Britain – to be shown on March 21 – I report that it is one that scarcely surfaces. The great trends of our times – globalisation and growing economic interdependence – cannot be stopped. Indeed, together with the multiplying possibilities of new technologies they present enormous opportunities. The problem is that British structures mean that our companies are losers in this game, when we could so easily be winners.

Whistleblowers run the risk of being accused of being protectionist and “anti-business”. So, for example, the car industry is routinely cited as an example of the brilliance of the sell-off strategy. India’s Tata and Germany’s BMW are doing for the old British Leyland what we could not do ourselves. The whole industry is now foreign-owned, and enjoying a remarkable renaissance, with 1.5 million cars now being assembled in Britain. Which is good – except that control now resides overseas where the profits necessarily flow and the strategic decisions are taken. For with ownership comes control, and the evidence is indisputable that those who control companies and assets have a bias to favour their own nations – even in an era of globalisation. There is “home country bias”. Professor Chris Higson of the London Business School reports research that 88% of the CEOs of the global top 500 companies and 85% of their management teams are nationals of the country where the company has its headquarters. These are the places where strategies are decided; where research and development is directed and economic activity located. Their migration abroad will see a continuation of the dumbing down of our economy that is already happening.

There is another lesson. With the right owners, British-based enterprise can flourish. The usual enemies of enterprise are routinely characterised as unions, taxes, regulation and the European Union. But the story the documentary tells is very different. The enemy of enterprise is the unowned, purposeless British company in thrall to myriad uncommitted, myopic shareholders. It is not because they are foreign that Tata and BMW succeed. It is because they are family-controlled with long-term, committed owners who have a clear vision and purpose.

Around the country, as the film shows, there are examples of similar British companies – but they are in a minority. There’s James Dyson, for example, spending a third of his profits on R and D. Or motor-racing entrepreneur David Richards; even the television-writer, Paul Abbott. All have sustained the ownership of their companies in their varying industries, kept control and driven them forward around a great purpose – doing what Tata and BMW do – and succeeding. The trouble is that in Britain everything militates against companies being able to demonstrate purpose and vision over time. Whether it is a problem with finding the finance to scale up from a fledgling start-up or defending your company from a hostile foreign takeover, the dice are loaded against visionary proprietors, founders and managers. The system is organised to favour transient, short-term shareholders who incentivise management teams to extract value from their companies, rather than build great ones.

Nor does the story end there. The current account deficit for the third quarter of 2014 – the latest reported – reached 6% of GDP, the highest since records began in 1955. Analysing the figures, the Office of National Statistics observes that one of the principal causes is the deterioration in Britain’s international investment position since 1980. For centuries Britain, courtesy of empire and overseas expansion, enjoyed a phenomenal net surplus of assets; we owned more of the world than foreigners owned us – so that consistently Britain netted a surplus of investment income.

No more. In the third quarter of 2014 the growing net deficit of assets as we sell off the country overseas meant that Britain had a record deficit in its investment income balance of 2.8% of GDP. If these trends continue for another 10 or 15 years the interaction with our growing trading deficit – we import a great deal more than we export – will eventually make the scale of our international debts and income flows abroad insupportable. There will have to be a massive national belt-tightening along with the imposition of controls of capital to stop a runaway sell-off of what will be valueless pounds. The curtain will come down on an era of amazing economic fecklessness.

That prospect is a good decade away, but the impact is already being felt. The ONS observes in a separate report on economic wellbeing that these huge transfers of income abroad are holding back the growth of our national spending power. Net national disposable income in the third quarter of last year was 5.8% below its pre-recession peak despite the economic recovery – in part, says the ONS, because so many of the benefits of growing economic activity are flowing abroad in dividends and payments to foreign owners.

I’ve set out ideas of how to change things in How Good We Can Be, published three weeks ago, but the precondition for any change is first the recognition of the problem. Selling off Britain is not a sign of success, as Conservative politicians like to portray it. It is a sign of profound structural weaknesses and will ultimately end in an economic debacle. Let’s at the very least start talking about it.