The party of Pakistani opposition politician Imran Khan has decided to resign all its seats in the country's national assembly, a senior official said Monday, amid a bitter row with the government over alleged election rigging.

Former cricket star Khan has rallied with thousands of supporters in Islamabad in recent days, demanding the government step down and hold fresh elections.

But the protest failed to attract the vast crowds Khan had promised and other opposition parties on Monday distanced themselves from his call for a campaign of civil disobedience, leaving him looking isolated.

"We are resigning from the National Assembly, Punjab Assembly, Baluchistan Assembly and Sindh Assembly," Shah Mehmood Qureshi, the vice-chairman of Khan's Pakistan Tehreek-e-Insaaf (PTI) party, told reporters.

He said the party was still making a decision about what to do in northwestern Khyber-Pakhtunkhwa province, where they are in power.

Qureshi did not give a timeframe for submitting the resignations.