Islamabad  - Pakistan's Prime Minister Yousuf Raza Gilani early Monday reinstated the country's top judge ahead of a showdown with opposition parties and defiant lawyers that threatened the stability of nuclear-armed country.

Former chief justice Iftikhar Chaudhry and his colleagues had been sacked in November 2007 under emergency rule proclaimed by then- president and military strongman Pervez Musharraf.

His removal triggered a mass movement against Musharraf, resulting in the defeat of his political allies in last year's elections, and ending his around nine-year military rule.

President Asif Ali Zardari, who replaced Musharraf, initially promised to reinstate the sacked top judge, but did not do so later on, turning himself into a highly unpopular political figure.

The reinstatement of Chaudhry came as tens of thousands of people were heading towards Islamabad in a massive protest rally from the eastern city of Lahore for a sit-in for an independent judiciary. (dpa)