The Jamiat Ulema-i-Islam-Fazl (JUI-F) 'Azadi March', led by its chief Maulana Fazlur Rehman to call for toppling the incumbent Pakistan Tehreek-e-Insaf (PTI) government, has set out from Karachi towards Islamabad.

Thousands of people, including seminary students, were participating in the march. In addition, convoys of political parties, including the Pakistan People's Party (PPP), the Pakistan Muslim League-Nawaz (PML-N), the Awami National Party (ANP) and others, joined the march on Sunday which commenced from Karachi's Sohrab Goth area, reports Dawn news.

Besides JUI-F leadership, PPP leaders Raza Rabbani, Saeed Ghani, PML-N leaders Mohammad Zubair, Nihal Hashmi, ANP's Shahi Syed and others, were onboard the leading container which is slated to reach Islamabad on Thursday.

Addressing the participants of the march, the JUI-F chief said that the opposition had denied all demands of the negotiation team sent by the PTI government and will hold their sit-in as per the decisions made by the judiciary.

"Prime Minister Imran Khan will have to resign. Hundreds of thousands have gathered in Karachi; what will the government do when people from across the country reach Islamabad?" he asked.

"I will announce the future course of action in Islamabad.

"We support positive politics. We have spent our entire life in loyalty to the country's Constitution and we have faced extremism (in return)," Rehman added.

Earlier on Saturday, the government and opposition inked a deal whereby the terms and conditions of the anti-government 'Azadi March' were chalked out, Dawn reported.

In a press conference, the head of the government's negotiation committee, Defence Minister Pervez Khattak reiterated Prime Minister Khan's promise that the participants will "see no obstacles" from the government as long as the protest is peaceful.

Fazl had announced in June that his party had decided to hold an anti-government long march to Islamabad in the month of October in a bid to topple the government, which he sad had come to power through "fake" elections.