The Supreme Court of Pakistan has been carrying on a multi-year battle with the ruling Pakistani People's Party,. The feud started when the Supreme Court ruled that party members did not have legal immunity from crimes commited in the past. The People's Party has continually challenged that ruling.
The Prime Minister Yousef Gilani has simply refused to implement the court ruling! In particular Gilani has refused to cooperate in a corruption case against Pakistani president Asif Zardari. Even after being presented with several ultimatums Gilani simply ignored the requests. Gilani insists that as head of state Zardari is above the law!
Even after the Supreme Court made the ruling aides to Gilani claimed it was meaningless. However the Electoral Commission agreed with the Supreme Court and so Gilani will definitely go. Whoever replaces him will face the same demand that the government cooperate with the corruption investigation into the president. For more see this article.