The Baird government's blueprint to force the merger of Randwick, Waverley and Woollahra into a beachside mega-council has riled locals with a football faux pas, declaring all eastern suburbs ratepayers support the Sydney Roosters.

The formal proposal for the controversial merger, lodged with the Office of Local Government, argues the three councils should be merged because of a "shared Eastern Suburbs identity".

Randwick Town Hall lit up for the Rabbitohs. Credit:Randwick City Council Facebook

The document cites the Sydney Roosters NRL club, which it says has "a strong following across the three council areas", as evidence.

"We certainly aren't Roosters," responded Randwick mayor Noel D'Souza. The council lights its town hall in the colours of the rival Rabbitohs.