"Why should we be monitored by other countries outside the Southern African Development Community when we are a sovereign state?" Mujuru was quoted as saying in the Sunday Mail.
The 15-member regional bloc brokered a coalition government between President Robert Mugabe and his arch rival Prime Minister Morgan Tsvangirai in 2008.
Mujuru said countries that have imposed sanctions against Zimbabwe wanted to "impose themselves on our national election processes to influence the outcome in their favour".
The European Union this week slightly eased sanctions against Zimbabwe but the United States said it will only end restrictions after more reforms.
Zimbabwe's official policy on foreign election observers is unclear. It rejected a report by EU observers, who slammed the 2002 polls for violence. They also said the elections were not free and fair.
Zimbabweans will vote March 16 in a referendum over a new constitution.
The charter will be a precursor to July polls to end a shaky Mugabe-Tsvangirai coalition.
Elections in Zimbabwe have been marred by human rights violations including killings of political opponents, beatings and intimidation. – Sapa