The freedom of Christians in Mali is at stake as the country prepares to vote on a new constitution on Sunday, an Open Doors partner has said. 

The referendum on Sunday is giving the people of Mali a say in whether the country should become a secular state.

Rev Dr Mohamed-Ibrahim Yattara, pastor and head of relief and development at national church body, Association des Eglises et Missions Protestantes Evangeliques au Mali, says the distinction between government and religious affairs is vital for the West African nation.

He is urging his flock to vote 'yes' on Sunday, in contrast to Muslims who are being urged by their imams to vote 'no'. 

"This new constitution is very important to us," he says.

"It defines what is freedom of religion. For us, this is a crucial issue."

The country is not officially Muslim but has moved in that direction since the 2012 rebellion in the north of the country, leading to a "precarious" situation today, says Open Doors.

"Many people are pushing to remove the word 'secular' from the Constitution," said Mohamed.

The referendum is taking place at a time of increasing tensions between Christians and Muslims. Radical Islamic groups have taken over the north of the country, displacing many Christians, Open Doors says. 

Mohamed said, "Many Muslims who go to Mecca or visit an Arabic country want to start a new mosque. Bamako is full of mosques, and there is a new Islam at large. It is a stricter and less tolerant Islam than the one we Christians lived alongside for so many years. I know many moderate Muslims feel the same way.

"Religion has entered into the public domain in a new way and that has changed everything.

"My fear, and the fear of many of my fellow believers is that we could end up living in a hard-line Islamic state, which enforces Sharia law. It will make every Christian in Mali fear for their future. This constitution, for all its other faults is our best chance of avoiding this."