Nawaz Sharif, former Pakistani prime minister, on Sunday night flew out of exile on a flight bound for Islamabad, promising to defy the government of General Pervez Musharraf, the president, and risk arrest to put his country on the path to democracy.

He made a symbolic and high-risk gesture by choosing to take a flight from London with Pakistan International Airlines, the national flag carrier, in a move that could be subject to political interference. Pakistan is due to hold parliamentary elections later this year or early in 2008.