Leaders of Germany's biggest union have approved their first major strike in seven years, starting in a region that is home to vehicle giant DaimlerChrysler. The decision by the huge IG Metall union's executive followed strike ballots in two German regions that produced overwhelming votes in favour of a walkout to press for higher pay. Economists fear the union's move could damage Europe's biggest economy just as it starts to emerge from recession. Any long dispute or hefty pay award could also rock Chancellor Gerhard Schroeder's bid to win a second term in office in elections to be held on September 22.