The Brihanmumbai Municipal Corporation (BMC) has issued notices to 26 shrines in the island city asking them to produce evidence that they are legal constructions or remove the respective structures within 48 hours.
If they fail to do so, the structures can be demolished without prior intimation.
Shiv Sena, the ruling party in the municipal corporation, has opposed the move.
The notices were sent to 23 temples, two mosques and a cross between Dadar TT and Kalachowkie area.
"We have sent notices to prove their legality. And the report will be submitted to the civic legal department for further procedure," said Harshad Kale, assistant municipal commissioner F-south ward.
Janhit Manch an NGO moved the Bombay High Court in 2002 asking for illegal shrines demolished alleging that many of them obstruct development work.
A year later, the high court ordered that all illegal shrines should be demolished.
Following the court order, the civic body submitted an affidavit to the high court saying it had demolished about 1,100 shrines.
"According to the court order we have issued notices to the shrines to produce documentary evidence to show the structure has been constructed with permission," Kale added.
Shiv Sena Executive President Uddhav Thackeray opposed the move. He said, "This can not be done."
He has also asked Mayor Shraddha Jadhav and Standing committee chairman Rahul Shewale to look into the matter.
Jadhav said: "No shrine has to be demolished when they have submitted their papers in 2003 to the civic ward offices."
Uddhav also said it is only Hindu temples that have become the target of civic authorities.