Pakistan’s embattled prime minister is facing a no-confidence vote in Parliament and the opposition said it has the numbers to win after Imran Khan’s allies and partners in the fragile coalition abandoned him.

The opposition needs a simple majority of 172 votes in the 342-seat Parliament to unseat the cricket star turned conservative Islamic politician. Mr Khan’s small but key coalition partners, along with 17 members of his own party, have joined the opposition to oust him.

The vote was expected to be held on Sunday after Parliament was scheduled to convene at 11.30am local time (0630 GMT), but Pakistan’s parliamentary rules allow for three to seven days of debate. The opposition said it has the numbers for an immediate vote, but Mr Khan’s party could force a delay.

On Sunday, giant metal containers blocked roads and entrances to the capital’s diplomatic enclave and to Parliament and other sensitive government installations in the capital.

A defiant Mr Khan called for supporters to stage demonstrations countrywide in protest at the vote. He has accused the opposition of being in cahoots with the United States to unseat him, saying America wants him gone over his foreign policy choices that often favour China and Russia.

He has also been a strident opponent of America’s war on terror and Pakistan’s partnership in that war with Washington.

He has circulated a memo which he insists provides proof that Washington conspired with Pakistan’s opposition to unseat him because America wants “me, personally, gone … and everything would be forgiven”.

A loss for Mr Khan would give his opponents the opportunity to form a new government and rule until elections, which are scheduled to be held next year. The opposition could also choose to call early elections.

Residents of Pakistan’s largest province, Punjab, are set to vote for a new chief minister on Sunday. Mr Khan’s choice faces a tough challenge and his opponents claim they have enough votes to install their choice.

With 60% of Pakistan’s 220 million people living in Punjab, it is considered the most powerful of the country’s four provinces.

Also on Sunday the government announced the dismissal of the provincial governor, whose role is largely ceremonial and is chosen by the federal government. But it further deepened the political turmoil in Pakistan.

Pakistan’s main opposition parties, whose ideologies span the spectrum from left to right to radically religious, have been rallying for Mr Khan’s ousting almost since he was elected in 2018.

Hi win was mired in controversy amid widespread accusations that Pakistan’s powerful army helped his Pakistan Tehreek Insaf (Justice) Party to victory.

Asfandyar Mir, a senior expert with the Washington-based US Institute of Peace, said the military’s involvement in the 2018 polls undermined Mr Khan’s legitimacy from the outset.

“The movement against Imran Khan’s government is inseparable from his controversial rise to power in the 2018 election, which was manipulated by the army to push Khan over the line,” he said. “That really undermined the legitimacy of the electoral exercise and created the grounds for the current turmoil.”

Pakistan’s military has directly ruled Pakistan for more than half of its 75-year history, overthrowing successive democratically elected governments. For the remainder of that time it has indirectly manipulated elected governments from the sidelines.

The opposition has also accused Mr Khan of economic mismanagement, blaming him for rising prices and high inflation.

Nevertheless, his government is credited with maintaining a foreign reserve account of 18 billion US dollars (£13.7 billion) and bringing in a record 29 billion dollar (£22.1 billion) last year from overseas Pakistanis. Mr Khan’s anti-corruption reputation is credited with encouraging expatriate Pakistanis to send money home.

His government has also received international praise for its handling of the Covid-19 crisis and implementing so-called “smart lockdowns” rather than countrywide shutdowns. As a result, several of Pakistan’s key industries, such as construction, have survived.

Mr Khan’s leadership style has often been criticised as confrontational.

“Khan’s biggest failing has been his insistence on remaining a partisan leader to the bitter end,” said Michael Kugelman, deputy director of the Asia Programme at the Washington-based Wilson Centre.

“He hasn’t been willing to extend a hand across the aisle to his rivals,” he said. “He’s remained stubborn and unwilling to make important compromises. As a result, he’s burned too many bridges at a moment when he badly needs all the help he can get.”

Mr Khan’s insistence there is US involvement in attempts to oust him exploits a deep-seated mistrust among many in Pakistan of American intentions, particularly following 9/11, said Mr Mir.

Washington has often berated Pakistan for doing too little to fight Islamic militants even as thousands of Pakistanis have died in militant attacks and the army has lost more than 5,000 soldiers. Pakistan has been attacked for aiding Taliban insurgents while also being asked to bring them to the peace table.

“The fact that it has such easy traction in Pakistan speaks to some of the damage USfor eign policy has done in the post 9/11 era in general and in Pakistan in particular,” said Mr Mir. “There is a reservoir of anti-American sentiment in the country, which can be instrumentalised easily by politicians like Khan.”