The question of reinstating senior judges sacked by President Pervez Musharraf under emergency rule in November remains central in Pakistani politics.
What's at issue?
Pressure has been mounting on President Musharraf to resign - he is adamant he is staying put.
Iftikhar Chaudhry - a thorn in President Musharraf's side
The country's biggest party, the Pakistan People's Party (PPP), has until now said the judges can only be restored through a constitutional amendment. It wants to reduce Mr Musharraf's presidential powers by the same means.
The country which came second in elections earlier this year, the Pakistan Muslim League - Nawaz (PML-N) of former Prime Minister Nawaz Sharif, wants Mr Musharraf impeached and the judges reinstated by a simple parliamentary resolution.
Why does it matter?
A number of judges, led by former Supreme Court Chief Justice Iftikhar Chaudhry, gained a reputation for judicial activism in recent years.
They investigated controversial privatisation deals and ordered the release of people who had been detained and "disappeared" in detention.
Things came to a head last year when the Supreme Court said it would rule on the legality of President Musharraf's re-election and an amnesty he granted former Prime Minister Benazir Bhutto, then the PPP leader, and her husband Asif Ali Zardari.
Mr Sharif was granted no such amnesty.
Why did Mr Sharif and Mr Zardari fail to agree on how to reinstate the judges?
Mr Zardari is now head of the PPP following his wife's assassination in December. He has been highly critical of Mr Chaudhry, accusing him of "playing politics". If the amnesty were overturned, he could face prosecution on corruption charges dating back to the 1990s.
He wanted the judges issue to be included in a wider package of constitutional reforms that would limit the powers of the president and the judges.
Members of the PPP say that most of the sacked judges were guilty of validating President Musharraf's 1999 coup and should be treated no differently from their replacements.
But Mr Sharif insisted that the judges be restored with the same powers they had before the state of emergency.
How serious has the issue become?
Some observers believe the differences between the two politicians are so serious that the governing coalition could collapse following the euphoria of their success in elections in which President Musharraf's supporters were trounced.
What does it all mean for President Musharraf?
President Musharraf has been seriously weakened over the past year by protests against his rule and by the rise of Islamic militancy in Pakistan.
He bowed to pressure at the end of last year and finally stood down as military chief.
Some analysts say he was hoping that the judges dispute would break the new coalition and strengthen him.
Mr Sharif is adamant that he should resign. Impeachment remains a possibility.
Some PPP members are worried that the powerful military would not agree to the impeachment of Mr Musharraf.
He still remains a key ally of the West in its fight against al-Qaeda and Taleban militants operating from Pakistan.
But many see his position as less secure now that he no longer heads the military in nuclear-armed Pakistan.
Is the judges issue important to ordinary Pakistanis?
Chief Justice Chaudhry became a rallying figure for most of Pakistan's lawyers, political parties and social activists last year who were opposed to President Musharraf.
His popularity plummeted as the economy got worse and Islamist militants became stronger.
Millions of poorer Pakistanis appear to be far more concerned now with alarming rises in basic food prices and are hoping that the new government will sort out Pakistan's economic problems fast.