Last week should have been a good one for George Osborne. The first day of April marked the day when the ”national living wage” came into force. The idea was championed by the chancellor in his 2015 summer budget when he said it was time to “give Britain a pay rise”.

Unfortunately for the chancellor, the 50p an hour increase in the pay floor for workers over 25 was completely overshadowed by the existential threat to the steel industry posed by Tata’s decision to sell its UK plants.

Instead of being acclaimed by a grateful nation, Osborne found his handling of the economy under fire. The fact that official figures showed that Britain has the highest current account deficit since modern records began in 1948 did not help.

At one level, all seems well with the economy. Growth was revised up for the fourth quarter of 2015 to 0.6% and is running at an annual rate of just over 2% – close to its long-term average and higher than in Germany, France or Italy.

The dogmas destroying UK steel also inhibit future economic growth | Will Hutton Read more

Two of three key sectors of the economy are struggling, though. Industrial production and construction have yet to recover the ground lost in the recession of 2008-09, leaving the economy dependent on services, which accounts for three-quarters of national output.

Digging beneath the surface glitter shows just how unbalanced and unsustainable the economy has become.

Growth is far too biased towards consumer spending. Borrowing is going up and imports are being sucked in. An enormous current account deficit and a collapse in the household saving ratio are usually consistent with the economy in the last stages of a wild boom rather than one trundling along at 2%.

A little extra digging provides the explanation, with some alarming structural flaws quickly emerging.

Here are two pieces of evidence. The first, relevant to the debate about the future of the steel industry, comes from an investigation by the left of centre thinktank, the IPPR, into the state of Britain’s foundation industries.

Foundation industries supply the basic goods – such as metal and chemicals – used by other industries. They have been having a tough time of it across the developed world, but the decline has been especially pronounced in the UK. Since 2000, the share of GDP accounted for by foundation industries has fallen by 21% across the rich nations that belong to the Organisation for Economic Cooperation and Development but by 43% in Britain. At the end of the 1990s, imports accounted for 40% of UK demand for basic metals; import penetration is now at 90%. Clearly, this trend will become even more marked if the Tata steel plants close.

The second piece of evidence comes from a joint piece of research from the innovation foundation Nesta and the National Institute for Economic and Social Research being published on Monday. This found that productivity weaknesses are common across the sectors of the UK economy, but particularly marked among newly formed companies. Fledgling firms tend to be less efficient on average, but the report said that in the years since the recession performance had been unusually poor among startups.

Since the economy emerged from recession, the growth of highly productive companies has been curbed and there has also been a slowdown in the number of under-performing businesses contracting in size. This helps explain why Britain has an 18% productivity gap with the other members of the G7 group of industrial nations.

According to the economic orthodoxy that has prevailed for the past four decades, none of this should be happening. The theory was that a good, solid dose of market forces would clear out the dead wood from the manufacturing sector; financial deregulation would ensure that funding was provided to young, thrusting startup firms; and free trade would ensure that British industry remained on its toes. Industrial policy would no longer be about “picking winners” but involve an open door to inward investment and low corporate taxes.

This approach has proved a complete dud. Successive UK governments have allowed good companies to go to the wall for the sake of their free market principles. They have squandered the once-in-a-lifetime opportunity provided by North Sea oil to modernise and re-equip the manufacturing sector. They have sat back and watched as the economy has stumbled from one housing-driven boom-bust to another. They have now arrived at the stage where house price inflation is running at 10% a year; the current account deficit in the latest quarter was 7% a year; and manufacturing is in recession.

The UK has been here before, although this time the numbers are scarier. Traditionally, what happens next is a sharp fall in the value of the pound, which helps rebalance the economy by making exports cheaper and imports dearer. Consumer spending takes a hit because goods cost more in the shops while manufacturers get a boost because their products are more competitive on world markets.

Such a depreciation would almost certainly be triggered by a decision to leave the EU in the referendum on 23 June. The assumption is that this would be a bad thing; in truth, a cheaper currency would be one of the benefits of Brexit.

But only in the right circumstances. There is more to rebalancing the economy and solving the UK’s deep-seated problems than simply devaluing the pound. If it was as easy as that, Britain would be a world beater by now. Getting the right level for the pound is a necessary but not sufficient factor in putting the economy right.

There is no shortage of ideas. Help for steel would be provided if procurement rules were tightened up so that contractors had to show they were sourcing sustainably, with the test being the impact on the environment and on local communities. The IPPR has a range of ideas for boosting foundation industries, including building stronger supply chains with advanced manufacturing and using the regional growth fund to provide more patient finance.

Nesta said its research shows the need for better targeted support for new companies rather than blanket measures such as cuts in business rates.

A new paper for the Fabian Society by the former Labour MP and leadership contender Bryan Gould believes there should be a twin-tracked approach: a 30% depreciation of the currency accompanied by a focus on credit creation for investment. This, he argues, could happen either through the existing banking system under the direction of the Bank of England or, if necessary, through a national investment bank. Gould says this is not about “picking winners” but about setting the parameters for possible good investment opportunities.

What links all these ideas is the belief that Britain needs a proper long-term industrial strategy. The prerequisite for that is an admission that the current model – low investment and competing on cost rather than quality – has failed, is failing and will continue to fail.