Shoppers in New York and sunbathers in Los Angeles looking up at the sky this week will find, traced over the cities in aircraft vapour, an unusual message: "Back to Germany".

This is the slogan for a campaign that has far-reaching implications for policy-makers in Germany and throughout the developed world.

The skywriting - as well as advertisements in the New York Times and a website (move-back.com) to be launched tomorrow - was commissioned by Wirtschaftsförderung Region Stuttgart GmbH, a recruitment agency in south-west Germany. It is aimed at German computer specialists thrown out of work when the US dot.com bubble burst.

This initiative highlights a growing dilemma facing the German authorities. In an apparent bid to win public support for mass immigration, Gerhard Schröder's centre-left government stressed the need for computer specialists from the developing world.

It was hoped this would not only plug a skills gap but also help erode the stereotypes of immigrants as unskilled. However, its 'Green Card' system, offering temporary residence to up to 20,000 information technology workers has been hit by the downturn in Germany's hi-tech sector.

Walter Rogg, the man behind the Stuttgart initiative, told the news magazine Der Spiegel: "We are arguing over ... legal regulation of immigration while forgetting our most important target group - the Germans who have gone abroad."