Prominent mayors have vowed to revolt against the State Government and voiced grave concerns about next week's local government reform announcement.
Mayors, many supporting change, say they will fight what they expect will be arbitrary boundaries Premier Colin Barnett plans to force on them.
Last-minute speculation on the future of several councils includes the carve-up of the City of Vincent between the Perth and Stirling councils; a Fremantle, East Fremantle and Melville merger and a potential amalgamation of the seven western suburbs councils of Cottesloe, Claremont, Subiaco, Cambridge, Nedlands, Mosman Park and Peppermint Grove.
Vincent mayor Alannah MacTiernan said she was a strong proponent of reform and had been expecting to merge with Perth.
Though her talks with Local Government Minister Tony Simpson indicated this, she now believed Mr Barnett had a different plan.
She said the Premier had said suburbs did not belong in the City of Perth so part of Vincent would most likely go to Stirling.
"If this happens we will know that it is Emperor Barnett behind the wheel - it will be a complete disregard of the Robson report and the submissions of the local governments," Ms MacTiernan said.
"Vincent is an inner-city council. Places like Leederville and Mt Hawthorn do not belong in a large suburban council."
All metropolitan mayors expect to hear their fate on Tuesday. Councils can potentially protest against boundary changes to force a community vote.
Fremantle mayor Brad Pettitt said he would fight "illogical" boundaries. "I support genuine reform but I do not support a sticky-taping of existing boundaries just for the sake of it," he said.
City of Bassendean mayor John Gangell said his council planned to merge with Swan but expected this agreement to be disregarded for a forced union with Bayswater.
Victoria Park and South Perth councils have also negotiated a merger. Talks with the minister centred on the river being a natural boundary but Victoria Park mayor Trevor Vaughan said the Premier saw Burswood as part of Perth.
Mr Barnett said his aim was to create stronger local governments.