She has degrees in museum studies and the history of art, but because of the economic crisis buffeting Spain, Montese Moya, 29, from Madrid, cannot find a job, even as a waitress. So in the spring she is travelling to London to try her luck.

She is not the only one. As youth unemployment rises — at 43 per cent, Spain has the highest in the European Union — Moya is part of a new, northward wave of migration from Mediterranean countries.

Maria Paredes, a 26-year-old journalism graduate, is another of the “lost generation”. She is leaving her home in Madrid soon and setting off for London too.

In Spain, Portugal, Italy and Greece, the overeducated but underemployed young are a worrying new demographic. Many live with their parents, unable to afford their own accommodation. Their dilemma is whether to stay in the bosom of their family, with the risk of a miserable future, or search for a better life elsewhere.

More and more are deserting their homelands, and not just for the north. Following in the footsteps of ancestors who colonised the pampas a century ago, 33,000 Spaniards have crossed the Atlantic to Buenos Aires over the past two years in search of work, according to one estimate.

Experts warn that the brain drain could have disastrous consequences: intelligent young professionals are what countries will need to emerge from the crisis.

Those who stay behind constitute a different sort of threat: violent anti-government protests by young people in Greece and Italy, as well as a spate of anarchist letter-bombings, have contributed to a sense of volatility in southern Europe as the best-educated people ever produced by those countries complain that they have become victims of their parents’ profligacy.

Even before the crisis, finding work in southern Europe was a challenge because of highly controlled labour markets, low wages and a high cost of living.

Unemployment among young Greeks is already over 30 per cent, and with the economy forecast to shrink by 3.6 per cent this year, things cannot be expected to improve.

As a consequence, seven out of 10 young Greeks between the ages of 22 and 35 are considering abandoning the country, while four in 10 are seeking jobs overseas, according to a recent survey.

Economists advocate a deregulation of the labour market to allow reduced payroll taxes and a cut in onerous sacking costs, which make businesses loath to hire workers on full-time contracts. Because of high employment costs, young people are often hired only on low-paying temporary contracts that do not provide the protection of full-time jobs. Making even minor changes to labour laws can involve endless negotiations between government, unions and employers all fighting tooth and nail to defend their interests.

As for Moya, she can think of at least seven friends who have left Spain in recent months. “Some have gone north,” she said. “Others have gone even further afield, to the Americas or Australia. It’s a sign of how desperate we are.”