Defa-e-Pakistan Council leader Maulana Sami-ul-Haq announced plans for the protest during a news conference in the garrison city of Rawalpindi.
The DPC will observe July 6 as a "black day" and organise a meeting of political parties on July 7 to finalise details for the march, he said.
Haq urged all religious and political parties to join the long march.
He contended that the reopening of the supply routes was "un-Islamic" since the materials transported through Pakistani territory to Afghanistan were "being used to kill Muslims".
The reopening of the routes goes against the sentiments of the Pakistani people and the recommendations of parliament, he claimed.
He demanded that the government should immediately resign as the reopening of the routes was not a "democratic decision of a democratically elected government".
Jamaat-ud-Dawah chief Hafiz Mohammad Saeed, his deputy Abdul Rehman Makki, Awami Muslim League chief Sheikh Rashid Ahmed and former ISI chief Hamid Gul were also present at the news conference.
Pakistan's top civilian and military leadership yesterday decided to end a seven-month blockade of the supply routes after the US apologised for a cross-border NATO air strike that had killed 24 Pakistani soldiers in November last year.
Islamabad had closed the supply lines after the NATO attack.
The DPC, which was cobbled together Hafiz Saeed last year, has been spearheading protests against the US and India across Pakistan.
The grouping has been accused of having links to the security establishment.
In a related development, the Hizb-ut-Tahrir and Jamaat-e-Islami chief Syed Munawar Hasan too condemned the reopening of the NATO supply routes.
Hasan claimed the government had put a seal on the "document of their slavery" to the US.
Hasan claimed the government had strengthened the enemies of Islam and Pakistan, forcing the people of Pakistan to rise up for their independence and to protect the country
