Catholics in Brussels are protesting against plans to close the majority of the city's churches.

The Brussels Catholic diocese reportedly plans to merge parishes and close local churches, moving Sunday mass to larger central churches, according to French website riposte-catholique.

Catholics wrote a letter to Archbishop Jozef De Kesel and his auxiliary, Bishop Jean Kockerols, asking them to renounce the plans, saying the proposed closure of churches would mark "the end of parish life".

In total, 108 churches are at risk.

The letter, which has over 20 signatories, says: "In a context where the priority of all political and social leaders is to strengthen local services and neighborhood life, does not this pastoral policy appear out of step with the desire to witness to a Church and a God who want to be close to man and the poorest in the heart of daily and ordinary life?"

The new strategy proposes "flagship churches" in strategic city locations with high quality services in order to increase attendance numbers.

This would suggest the Catholic Church is declining in Brussels, but the writers of the letter quoted statistics pointing to a rise in baptisms and seminarians in recent years.

"Is there a lack of succession? 55 seminarians for the Diocese of Malines-Brussels and the many foreign priests that drive foreign Catholic communities, this is doubtful," they wrote.

Instead they suggested the faithful might "mobilise all together" to create "a wonderful engine capable of revitalising the ecclesial fabric and a wonderful vehicle to announce all the Good News of Christ 'to the outskirts'.

"We can together transform the difficulties," they said.