April 3: Pakistan's Prime Minister Imran Khan has urged the president to dissolve parliament and call fresh elections following an opposition attempt to remove him from office.

It follows chaos in parliament over a no-confidence move against him.

Parliament's deputy speaker refused to hold a vote on the motion which the PM was expected to lose.

Khan has alleged that the attempt against him is part of an international conspiracy orchestrated by the US.

The BBC's Secunder Kermani says the prime minister is widely regarded as having come to power with the help of Pakistan's army, but now observers say they have fallen out.

His political opponents seized the opportunity, after persuading a number of his coalition partners to defect to them.

Khan alleges US officials have warned Pakistani diplomats that the prime minister must be removed from power because of his foreign policy decisions, such as recently visiting Moscow to meet President Vladimir Putin and his previous criticism of America's "War on Terror".

Opposition politicians ridicule the allegation, and the US has denied there is any truth to it.

What happened in parliament?

Information Minister Fawad Chaudhry told MPs that every Pakistani citizen had a duty of loyalty to the state, based on Article 5(1) of the constitution.

Developing the prime minister's allegations of a foreign conspiracy, Chaudhry said foreign ambassadors were told a day before the opposition filed for a motion of no-confidence against Khan that such a move was forthcoming.

"We were told that relations with Pakistan were dependent on the success of the no-confidence motion. We were told that if the motion fails, then Pakistan's path would be very difficult. This is an operation for a regime change by a foreign government," Chaudhry said, urging the deputy speaker to decide if a vote was constitutional.

The deputy speaker then proceeded to declare it was not.

Opposition MPs are furious and have refused to leave the chamber.

Chairman of the Pakistan People's Party Bilawal-Bhutto Zardari lawyers were on their way to the Supreme Court to challenge the government.

"The united opposition is not leaving Parliament. Our lawyers are on their way to Supreme Court. We call on ALL institutions to protect, uphold, defend and implement the Constitution of Pakistan," he tweeted.