Madagascar's highest court gave the go-ahead on Wednesday for a referendum on a new constitution before presidential elections pledged by the government.

The administration led by Colonel Michael Randrianirina said it would hold elections within 24 months of ousting President Andry Rajoelina in October 2025 after weeks of protests.

A date for the poll on the Indian Ocean island has not been set.

"Holding a referendum on changing the constitution before the presidential election is not contrary to constitutional provisions," the High Constitutional Court (HCC) said.

Various options for a new constitution have been discussed including a shift to a federal state, which appears popular among younger people behind the "Gen Z" protests that led to Rajoelina's ousting last year.

Another option that has been raised is for a "strongly decentralised" state.

The current constitution was approved in a referendum in 2010 following the overthrow of President Marc Ravalomanana after protests led by Rajoelina.