Now we must welcome the best and brightest

As with any sporting spectacular, there is intense rivalry over who will get the glory. David Cameron was first out of the blocks, claiming the Olympic festivities will boost the economy by £13 billion, despite evidence showing such events hinder rather than help growth. At the weekend, Boris Johnson stepped up the pace, saying the Games were a fantastic investment and he was determined to use the occasion to sell London to the world.

Having inherited this gift from their Labour predecessors, both the Prime Minister and the Mayor would be failing in their duty if they did not do everything to bang the drum for London and the Olympics — even if costs have risen fourfold amid economic gloom.

Yet at this moment of triumph, when we are welcoming the world and displaying the capital’s finery, we are sending out precisely the opposite message, with a self-defeating stance of hostility to those wanting to visit.

Fuelled by an irrational fear of immigration, Britain has an over-loaded, incompetent and clapped-out visa system that is economically insane at a time when we are searching for growth amid intense global competition.

The chaos at Heathrow is merely the tip of a nasty iceberg, the visible end of a process so torturous that one in four people abandon plans to come here.

We are deterring students who want to study in our universities, business people who want to trade, tourists who want to spend in our shops and even musicians who merely want to entertain us (efforts to ease the problems for visiting artists during the Games are unlikely to be sustained).

Many problems arise from the immigration cap, which aims to reduce the number of net newcomers from outside the European Union to 100,000 a year. In opposition, the Tories argued that poorly designed targets were blunt instruments that distort priorities; in office, this policy has proved their point.

The cap will cost universities up to £8 billion a year, with some institutions already recording a 30 per cent fall in applications. So it was little surprise to see 37 prominent business leaders yesterday join the chorus of concern over something so clearly damaging to Britain’s long-term interests.

To make matters worse, the dunderheaded Home Office imposed new restrictions this year on foreign students seeking postgraduate work, encouraging the brightest and best to go elsewhere. This highlights the horrors of obtaining a British visa, with people spending £600 and having to wait five months while their application slithers through a sclerotic system.

Many have been left in limbo, unable to work in Britain or to go home while their passports are being processed. Smart young Americans and Indians complain of losing good jobs, and express rising resentment against a nation that took their cash for university fees then treated them so contemptuously.

Our official face is just as inhospitable to those wanting to come here to do a business deal or sightsee, with a visa system judged to be the worst in Europe.

It is more expensive, more complicated and takes longer to process than the Schegen visa, which gives access to 26 European countries. Africans, Brazilians and Chinese must be prepared to take several days off work should they wish to come here, so it is little surprise many abandon the process.

Supporting documents must be translated into English and passports handed over for up to a month — which for business people or performers can mean a month without work. On top of all this, inspectors found applicants  were turned down for failing to supply information that was never requested.

Visit Britain says this inept system costs Britain £2.8 billion a year in lost tourist revenue. The damage can be seen most clearly with the Chinese,  who now travel abroad in huge  numbers — 78 million this year compared with 12 million a decade ago. Yet eight times as many go to France as to Britain, costing this country dearly.

The Chinese are, according to one survey, the world’s biggest shopaholics, spending eight times as much as Britons on a trip to the West End and even outspending Americans and Russians. This is why top department stores have Mandarin-speaking sales assistants and accept UnionPay, the Chinese debit card.

Given such figures, it it little wonder that the Prime Minister and Culture Secretary are trying to persuade the Home and Foreign Secretaries to sort out the mess. Australia can complete online visas in a day — although in truth we could abandon them for many of the 108 nations that currently need them.

They need to fix things fast. For cities are delicate creatures with fragile ecosystems. Amid all this hoopla, it is easy to forget London was in decline for nearly four decades after it last held the Olympics in 1948, its economy waning and population shrinking fast.

This was the bleak city of my childhood, a world apart from the exhilarating place showing off this weekend. It was revived by the much-maligned force of globalisation as it became an international and multicultural city.

The influx of hard-working, high-spending and well-qualified foreigners helped London soar even as Britain’s standing in the world slipped. These are the people ensuring the capital can prop up the rest of the country. And these are the people we seem uncomfortable about having in our midst, especially given our own propensity to live, work and travel abroad.

We need to turn these honeyed words of Olympic welcome into a genuine greeting to visitors wishing to shop, sightsee, study and trade. Otherwise, the long-term damage could be even more profound than the short-term economic costs, endangering the future wellbeing of the capital even as it hosts the greatest party in its history.