Pakistan plunged towards a debilitating power struggle yesterday as the Supreme Court destabilized a provincial government controlled by President Asif Ali Zardari's main rival, former premier Nawaz Sharif.

The court's decision to nullify the election last year of Nawaz's younger brother Shahbaz Sharif as Punjab's chief minister raised fears of a return to the political instability of the 1990s, a decade that ended in a military takeover.

It wiped five percent off share values on the Karachi stock exchange.