Nouakchott - Mauritanian President Mohamed Ould Abdel Aziz launched a campaign on Friday for a constitutional referendum boycotted by opposition figures who call the vote a smokescreen to keep the ruling party in power.
The boycott movement draws broad political support from Islamists and anti-slavery activists in the conservative west African nation, all of whom oppose measures including abolishing the senate and changing the national flag.
"Your presence in such great numbers sends a message to those who don't want the country to move forward," Aziz told large crowds in a stadium close to the capital, Nouakchott, according to an AFP journalist at the scene.
Aziz said he would travel the length and breadth of the country to "respond to the lies and hoaxes" of his opponents.
Senators rejected the abolition of their own chamber in March, apparently to the government's surprise as a majority are from the ruling party, prompting Aziz to call the referendum.
The visibly irritated president hit out at the lawmakers in his Friday speech, saying they had "done much harm to the Mauritanian people."
The boycotters will not be allowed airtime accorded to those involved in campaigning for the referendum, an official within the country's authority controlling the press and broadcast media confirmed to AFP.
Sections of the opposition fear that despite Aziz's claims to the contrary he is laying the groundwork for a third term in power, with his own prime minister saying recently he supported the idea.
More than 1.4 million Mauritanians are eligible to vote on the constitutional changes.