Large sections of Royal Park could be dug up to lay freeway tunnels and construct overpasses as part of the massive construction program linking the Eastern Freeway to CityLink.

New state government documents show a massive impact zone for the proposed freeway covering most of Royal Park.

The multibillion dollar freeway is the state government's number one transport priority and the new East West Link documents were lodged with the federal government as part of the environmental approval process.

The freeway work is expected to lock the public out of sections of Royal Park for years and it is not clear if areas of the park will be lost permanently.