While voters in France and the Netherlands, two of the founders of the European Union, are questioning the benefits of membership before referendums on Europe's new constitution, Norway, one of Europe's richest countries, increasingly feels it is paying the price for remaining outside the club.

Its immediate concerns stem from a decision by the EU to put a 16 per cent duty on Norwegian salmon, one of the country's chief exports. The duty, which came into force last week, could become a "permanent" tariff should an anti-dumping investigation by Brussels conclude Norway has been selling its salmon inside the EU at below the cost of production.