The apex court also declared the election of Sharif's brother, Punjab Chief Minister Shahbaz Sharif, null and void, which will force him to step down as chief minister of Pakistan's most populous province. In a verbal order, a three-member bench led by Justice Musa K Leghari dismissed all petitions challenging the Lahore [Images] High Court's order disqualifying Nawaz Sharif from contesting the elections.

The Lahore High Court had earlier ruled that Nawaz Sharif, who was overthrown in a coup by former president Prevez Musharraf, was ineligible to stand in a by-poll because of previous criminal convictions. The court decision is likely to deepen a growing rift between Sharif and the new government headed by President Asif Ali Zardari [Images]. Though the judgment against Sharif would not directly affect a year old Pakistan People's Party-led coalition government, the ruling against the younger Sharif could spark off a power struggle in Pakistan's richest province of Punjab, where the Pakistan Muslim Laegue-Nawaz is in coalition with the PPP.

The Sharif brothers did not immediately say whether they will move the Supreme Court to review its judgment, but they have refused to appear before the court in person, casting doubts on its legitimacy to hear the case. The main opposition PML-N reacted angrily to the judgment, with party spokesman Siddique-ul-Farooq saying, "We do not recognise these courts as genuine and constitutional courts. These are kangaroo courts and we care a fig for this judgment. It has no value."

Farooq said the judgment also proved Sharif's allegation that Zardari was conspiring to get the Sharif brothers disqualified from contesting polls through 'kangaroo courts'.

Senior PML-N leader Khawaja Asif, a close aide of Sharif, said, 'Some people in the Pakistan People's Party have chosen to draw the battle lines' and the PML-N would have 'no option but to fight back'.

Addressing a general council meeting of the PML-N last week, Sharif had accused Zardari of conspiring to get him and his brother Shahbaz disqualified from contesting polls. He also cautioned Zardari not to get involved in conspiracies against the PML-N leadership.

Sharif, a two-time prime minister, was barred from contesting last year's general election and subsequent by- polls due to his conviction in a criminal case filed against him by the regime of former military ruler Pervez Musharraf [Images].

That case related to charges of conspiring to hijack an aircraft that was bringing Musharraf back to Pakistan from a foreign trip in 1999. It was filed after Sharif was deposed by Musharraf in a military coup in October 1999.

Petitions were also filed challenging Shahbaz's eligibility to contest polls due to charges of involvement in a case of extra-judicial killings. However, Shahbaz was later acquitted in that case. A high alert was sounded in the federal capital before the apex court gave its verdict and the paramilitary Pakistan Rangers were deployed at sensitive locations.

PML-N activists said the party's top leadership would meet soon to take stock of the situation and decide their future course of action. Party spokesman Farooq said, "The court of the people of Pakistan is the real court and we are confident that they have given their verdict in favour of PML-N leaders."