Christian groups in mainly-Muslim Indonesia are planning legal action over laws barring them from building new churches.
They plan to lodge a class action against Indonesia's government, accusing it of discrimination by continuing to enforce a decades-old decree governing construction of new places of worship.
The decree, issued in 1969 by the then religious affairs ministry and the home affairs ministry, violated human and religious freedom principles, they said.
"The decree is contrary to Article 29 of the Constitution, which guarantees citizens the right to choose their belief and perform their religious duties," Indonesian Communion of Churches chairman Nathan Setiabudi told the Jakarta Post.
The decree requires a religious community to gain approval from local government before building a new church or some other place of worship.
The local authorities can then consult other local religious communities before approving the proposal, creating a tough hurdle for Christians in the world's most populous Muslim nation.
"We have been trying to build a new church close to my home for years," Jakarta gym instructor Darwin - a Christian - told AAP.
"Every time the government seeks approval from the local mosques, they refuse."
Muslims account for about 85 per cent of the country's 215 million people.
The lawyer representing Christian organisations, Habiburokhman, said he would file the class action with the Central Jakarta District Court at the end of this month.
"We shall ask the government to revoke the ministerial decree and apologise to affected citizens," he said.
At the same time, the government is also under fire about a new and Orwellian-named Religious Tolerance Bill, which will also restrict the building of new churches and effectively prohibit Muslims from converting to other faiths.
Critics have warned the bill, aimed at preventing proselytising, is part of a campaign by fundamentalists timed to coincide with national and presidential elections this year and push Indonesia further towards becoming a full-fledged Islamic state.
In some cases, local Muslims in Jakarta have forced churches to close their doors on the basis of a 2002 government regulation allowing them to be shut down if local residents objected to their presence.
Masdar Mas'udi, the acting head of Indonesia's largest Muslim group, the 40-million strong Nahdlatul Ulama, said he would study the 1969 decree and decide whether to support its scrapping.
"If its implementation discriminates against certain religious groups and fails to uphold justice, the government should withdraw it," he said.
But he said he suspected the same discrimination occurred in predominantly Christian parts of Indonesia such as Papua and West Timor.