Christian leaders have written to the Welsh Government seeking guarantees that churches will not be forced to close again should further lockdowns be introduced in Wales.
Churches are banned from hosting services with a congregation during the 17-day firebreak.
Earlier this week health minister Vaughan Gething would not speculate on whether further lockdowns would happen early next year.
Under the firebreak regulations all places of worship are closed until November 9.
Weddings, civil partnership ceremonies and funerals will continue to be held during the firebreak.
The regulations also allow faith leaders to broadcast services from places of worship in the absence of a congregation.
The church leaders, who work in some of the most deprived areas of Wales, have written to the Welsh Government again seeking assurances that any future legislation would "respect the principle of church independence, and in particular, would not impose a legally binding ban on church services".
They are also seeking a meeting with First Minister Mark Drakeford to discuss the issue.
Rev Clyde Thomas, leader of Victory Church in Cwmbran, said: "We are deeply concerned by the likelihood of a second firebreak in January and need dialogue and reassurances.
"The likely firebreak in the new year would come at a time when the highly vulnerable people we serve in our community need us most.
"The church must have the freedom to worship and to be open so that we can support our communities physically, emotionally and spiritually."
The church leaders are being supported by the Christian Legal Centre.
Chief executive Andrea Williams said: "We call on the first minister of Wales to meet with these church leaders to discuss how the long-held constitutional principle of the independence of the church and its role within society will be upheld in Wales moving forward."