Victoire Ingabire, the leader of the unregistered United Democratic Forces party who faces charges of crimes linked to genocide denial, told Reuters Kagame faces little competition and is set to easily secure a second seven-year term.

"I will not vote and I will ask the population 'don't vote' because we know before the election who will win," she said.

She said her absence on the ballot paper would render Kagame's victory illegitimate.

Kagame is widely lauded outside Rwanda with restoring stability and rebuilding the central African nation in the aftermath of the 1994 genocide, and for his bold ambition to transform Rwanda into a middle income country by 2020.

"Elections do not mean democracy. If we want to start a democracy we have to allow an opposition to be active," Ingabire said.

Kagame will compete against Damascene Ntawukuliryayo from the Social Democratic Party (PSD), Prosper Higiro from the Liberal Party (PL) and Alvera Mukabaramba from the smaller Party of Progress and Concord (PPC).