"There is no country in SADC (the Southern African Development Community) that can stand up and say Zimbabwe has faulted. SADC does not do that, it is not a court but an organisation of 14 countries that co-operates with each other and supports each other."
Tsvangirai's arrest and subsequent assault on March 11 while trying to attend an anti-government rally was widely condemned by the West but the SADC summit, which was meant to address the crisis in Zimbabwe, ended up with a statement of "solidarity" with the 83-year-old Mugabe's government.
Mugabe was chosen to stand for re-election after a lengthy closed-door session of the party's central committee in the capital Harare.
"The candidate for the party in 2008 will by the president himself. He was endorsed by the central committee," Nathan Shamuyarira, party spokesman, told reporters after the meeting.
"That is the sum decision taken today," he added in a brief statement.
Mugabe, widely blamed for the political and economic crisis rocking Zimbabwe, would remain president until the age of 90 if he were to be re-elected and serve a full six-year term.
While there have been rumblings of discontent within ZANU-PF towards Mugabe, no-one has so far put their head above the parapet to challenge his nomination.