Islamabad  - Pakistan's government Saturday announced a proposal that it hopes will calm growing political tensions in the nuclear-armed country.

The announcement came after US Secretary of State Hillary Rodham Clinton placed separate calls to Pakistani President Asif Ali Zardari and opposition leader Nawaz Sharif, in last-ditch efforts to end a stand-off between them over the restoration of a top judge sacked by former military strongman Pervez Musharraf in 2007.

Aside from the nation's nuclear capabilities, Pakistan has also become a key US ally in the international fight against terrorism. That has only increased US concerns as tensions rose in Pakistan.

According to a statement from Zardari's office, the government has agreed to address the issue of restoration of judges by adhering to principles agreed upon in a charter of democracy signed in 2006 betwen Sharif and Zardari's slain wife and ex-premier Benazir Bhutto.

However, the document only pledges an independent judiciary and restoration of democracy, not the reinstallation of the judge in question, a point that has not gone unnoticed in Sharif's camp.

An alliance of opposition parties, led by Sharif and the influential legal community, has launched a cross-country march scheduled to reach Islamabad on Monday to force Zardari to fulfill promises to reinstate Iftikhar Chaudhry, an independent-minded judge, and several of his colleagues.

The massive demonstration in Islamabad could attract tens of thousands of protesters and result in political chaos.

Sharif threw his weight behind what was originally a lawyers' movement in February, after the country's Supreme Court barred him and his brother Shahbaz Sharif from elected office. He said he believes Zardari ordered the verdict, an accusation the government flatly denies.

Zardari has tried to suppress the protests by ordering the arrest of more than 1,000 activists. Thousands of paramilitary troops have also been called out in Islamabad while law enforcement agencies have seized thousands of containers and trucks to block roads.

An army spokesman said the government has put military troops on standby to control the protests. "These can be deployed in sensitive areas of some districts if the situation gets out of control," Major General Athar Abbas said.

This has raised concerns in Washington and other Western nations, which want Pakistan to focus on the fight against Taliban and al- Qaeda militants who sometimes launch cross-border attacks on US-led international forces in Afghanistan from Pakistan.

US and British diplomats have tried to broker a deal between Sharif and Zardari. Pakistani military chief General Ashfaq Parvez Kayani is also part of the reconciliation efforts that were intensified on Saturday.

However, Zardari showed flexibility only after receiving a phone call from Clinton who, according to media reports, expressed deep concern over the deepening political crisis in Pakistan.

Under the proposed compromise package, Zardari's government will try to reverse the controversial ruling against Sharif brothers.

"The federal government will file a review petition in the Supreme Court against the verdict of the Supreme Court disqualifying Mian Nawaz Sharif and Mian Shahbaz Sharif from electoral politics," the statement said.

The Sharif brothers' Pakistan Muslim League-Nawaz (PML-N) party welcomed the announcement with scepticism.

The charter of democracy doesn't say anything about the restoration of judges, it only talks about the appointment of an independent judiciary, read a statement from PML-N.

"The government must clarify whether it would restore the deposed judges or not. Sharif's qualification is not the issue, currently. The basic issue is restoration of judges," it said further.

Meanwhile, opposition parties and anti-government lawyers were in the midst of their cross-country march Saturday, travelling through the eastern province of Punjab en route to Islamabad.

Around 2,000 black-suited lawyers gathered in the central town of Multan, where they scuffled with riot police who stopped them from embarking on their journey to Punjab's capital, Lahore. They chanted slogans like "Death to Zardari," "Zardari is a dog" and "restore the chief justice."

Zardari has ordered a blockade of transmissions of the country's most popular Geo news channel in many cities, the broadcaster reported. The government has denied the blockage.

The hard-handed tactics triggered criticism from rights activists and even dissent within Zardari's own Pakistan People's Party (PPP).

Information Minister Sherry Rehman resigned Friday night after failing to persuade Zardari to lift the ban on telecasts. Rehman is the second minister to resign from the cabinet in less than two weeks. (dpa)