Pakistani opposition leader Imran Khan on Sunday took the campaign to unseat Nawaz Sharif to the prime minister's home base of Lahore, where tens of thousands of people roared their support for change.

Pakistan has been in turmoil since August when protesters led by Khan, a former cricket star, and Tahir ul-Qadri, a firebrand cleric, stormed into the capital and occupied an area home to government buildings and foreign embassies.

In the latest twist, Khan organized a major rally in Lahore, Sharif's political base, saying protests would continue around the country until the government quits.

"Nawaz Sharif should hurry up with his resignation while I wake up Pakistan by organizing public protests," Khan told a roaring crowd of up to 100,000 in Pakistan's cultural capital.

"I am thankful for Lahoris for their massive support. Lahoris have not left me, I will always stand by the Lahoris. I will continue the (protest) until Nawaz Sharif resigns."

The persistent protests have become an embarrassment for Sharif in a military coup-prone nation, with some in the prime minister's administration accusing the powerful army of instigating the movement as a way of weakening Sharif.

The army has denied meddling in civilian affairs, saying it is neutral, but in a country ruled for half of its history by the military, most commentators agree it is ultimately up to the army to decide how the crisis ends.

The protest leaders accuse Sharif of rigging last year's election which brought him back to power in a landslide, a charge he denies.

The confrontation turned violent last month, with thousands trying to storm Sharif's house in the capitalIslamabad and briefly taking the state television channel off the air.

Unrest in Pakistan is a worry to regional powers who are concerned about more political violence in a country bordering Afghanistan, where most foreign troops are due to leave this year following more than a decade of war against the Taliban.

Khan is a charismatic Oxford graduate whose populist slogans have struck a chord with many Pakistanis fed up with incessant power cuts and lack of job opportunities.

"I have decided to support Imran (Khan) because he is an honest and brave person," said Sher Shah, a 21-year-old student. "His recent speeches ... inspired me and I believe he can bring change to Pakistan."