Former premier Nawaz Sharif and Pakistan People's Party co-chairman Asif Ali Zardari are expected to meet shortly to discuss the formation of a coalition government if they emerge victorious in the general election on Monday and the possibility of organising joint protests in case the polls are rigged.

At their last meeting on February 12, Zardari and Sharif, the PML-N chief, had said they would form a coalition government if they emerge as the largest groups in the February 18 polls, in order to prevent the military from usurping power from elected representatives.

Sources in the PML-N said the two leaders would also discuss the possibility of organising joint protests in case the polls are rigged. They said the meeting would be crucial as the two parties are expected to perform well in the elections to the national and provincial assemblies.

However, observers said the two parties are yet to resolve their differences over several key issues, including the reinstatement of judges who were deposed during last year's emergency rule. The PML-N has vowed to reinstate the judges while the PPP has only committed itself to the independence of the judiciary.

Despite allegations of rigging from the opposition, President Pervez Musharraf [Images] has vowed to hold free and fair polls. He has also warned that there would be zero tolerance for protests during and after the elections and parties should accept the results thrown up by the polls.

PPP leaders have threatened to launch street protests if their party does not win the polls, saying this would be evidence that the general election was rigged.