By Syed Shoaib Hasan
BBC News, Islamabad
Police in Pakistan have arrested dozens of activists belonging to former Prime Minister Nawaz Sharif's party.
Mr Sharif has spent most of his exile in the UK and Saudi Arabia
Mr Sharif was deposed and exiled in a 1999 coup by Pakistan's current leader, Gen Pervez Musharraf.
Mr Sharif announced last week that he would return to Pakistan on 10 September after seven years of exile.
Meanwhile, talks between the government and another former Prime Minister, Benazir Bhutto, and her Pakistan People's Party have resumed in the UAE.
"Our activists are being arrested all over the Punjab," Ahsan Iqbal, PML-N secretary of information, told the BBC.
"At least 100 have been arrested so far."
Sharif's supporters in Pakistan were ecstatic to hear he was returning
The arrests started on Saturday on the orders of Punjab's Chief Minister, Chaudhry Pervez Ellahi.
Mr Ellahi belongs to the ruling PML-Q political party.
With his cousin and PML-Q President Chaudhry Shujaat Hussain, the party has formed the backbone of President Musharraf's government.
But that is threatened by the return of Mr Sharif.
Most PML-Q parliamentarians, including the cousins, are former PML-N members and defected after Mr Sharif went into exile.
With his release now imminent, the defectors seem quite willing to return to the party fold.
Observers believe a strong show of public support when Mr Sharif reaches the country could effectively ruin the PML-Q.
This, Mr Iqbal believes, is why his party members are being rounded up.
"Last night the police raided the house of our Rawalpindi president, and harassed... his family."
The arrests come as the government tries to arrive at a political deal with Pakistan's largest political party, the PPP.
The PPP has been part of the opposition during Gen Musharraf's regime.
But since President Musharraf was weakened by a storm of political protests following his failed attempt to sack the country's top judge, the PPP has emerged as an unlikely ally.
But recently, negotiations between the two parties ran into troubled waters.
Ms Bhutto announced that talks had broken down, and she would soon be returning to Pakistan.
Observers say this may have been precipitated by Mr Sharif's imminent return and accusations that she was selling out to the army.
But the negotiations now appear to be back on track.
Analysts say they represent the last chance for President Musharraf to maintain his grip on power.