The demonstration in Lahore, Pakistan’s second-largest city, came as an 11-party coalition called on Mr Khan to resign and for fresh parliamentary elections to be held, just two years after the former cricket star won power.
The protesters, mainly low- and middle-income Pakistanis, have rallied to the opposition’s call amid rising anger at high inflation and poor economic prospects under Mr Khan’s leadership. .
“There was a time when I could pay for food, rent, electricity and gas from a days’ labour,” said Arif Mehmood, an Islamabad taxi driver. “Now what I earn in a day mostly goes to food.”
The movement has been boosted by support from Nawaz Sharif, the former prime minister, who was removed in a supreme court verdict in 2017 on corruption charges. Mr Sharif, who has been in London since late last year for medical treatment, has accused General Qamar Javed Bajwa, Pakistan’s army chief, of influencing the 2018 polls.
“No army can fight its own people,” said Mr Sharif in a video message broadcast from London and played at Sunday’s rally.
“One freedom was what we won in 1947 [the creation of Pakistan]. Now is the time to win our freedom again,” he said, “I urge young people to come out of their homes [for the cause of democracy]”.
Opposition leaders have also threatened to resign en masse from parliament and organise a march to Islamabad next month in an effort to paralyse the Pakistani capital.
Mr Khan has offered to negotiate with the opposition but has refused to drop corruption charges against former leaders, including Mr Sharif. “Having never worked a day in their lives, their shahi [royal] lifestyles are directly dependent on saving their families’ ill-gotten, illegally acquired wealth through robbing and impoverish[ing the nation,” he wrote on Twitter last month.
Maryam Nawaz Sharif, Mr Sharif’s daughter, who is leading her father’s Pakistan Muslim League party, called the rally “decisive” in a television advertisement broadcast ahead of the protest.
“You have to decide either to seize your rights or continue living under the worst government. You will have to decide against inflation, growing prices of food items and economic breakdown,” she said.
The pandemic has heaped pressure on a fragile economy. Disbursements under a $6bn IMF loan programme have stalled after Mr Khan refused to accept further harsh measures including higher taxes, energy tariffs and interest rates.
“As long as the political momentum keeps growing against the government, it would be difficult for the prime minister to meet the IMF’s demands,” said Sakib Sherani, a former adviser to the finance ministry.
Separately, a government minister with direct knowledge of the situation said China had agreed to provide further lending to help repay loans to Saudi Arabia.
Saudi Arabia pledged $6.2bn to Pakistan for three years, including $3bn of cash and a $3.2bn oil swap facility, just after Mr Khan took office in 2018.
But Riyadh asked Islamabad to pay back $1bn and it froze the oil credit facility in July amid a deepening diplomatic dispute. China stepped in to help Pakistan make the repayment.
Saudi Arabia requested a further $2bn in early December, according to government officials, who said Beijing would loan the money to Islamabad to make the payment.