The Baird government will spend $12.6 million spruiking the Sydney Metro to the public, signing contracts with five consultancy firms to manage community relations ahead of a wave of compulsory property acquisitions and demolitions.

The attempt to win public support for the disruption set to engulf the city and south western suburbs as it builds Australia's biggest rail project ranges from "classroom-ready" lessons for schools to traditional "spin".

Protests against the Baird government's big infrastructure projects, as construction sites sweep across Sydney, have grown.

On Sunday Lucy Turnbull's Greater Sydney Commission will separately launch an "Our Sydney/Your Home" campaign, in a belated attempt to win back community support for change.