The move would see the number of beds for mental health across the county cut from 707 to around 450.
Under the plans, facilities at Parkwood at Blackpool Victoria Hospital and units at Lytham and Fleetwood hospitals would close and be replaced by a state-of-the-art hospital.
The site of the soon-to-be closed Devonshire Road Hospital in Blackpool has already been mentioned as a possible location.
Michael Jack, MP for Fylde, said he welcomed the review of services.
He said: "I'm pleased the provision of mental health services is being looked at. It has been something of a Cinderella service."
Joan Humble, MP for Blackpool North and Fleetwood, echoed his response.
She said: "I will be looking carefully at the document because you've got to get the balance between the number of in-patient beds for people with mental health problems and local support in the community."
Lancashire Joint Primary Care Trust, which is proposing the changes, has blamed ageing and poor conditions in the existing units.
Its report states: "Currently the mental health facilities across the Fylde coast are very cramped with Parkwood needing significant changes and modernisation to meet basic standards of privacy and dignity.
"There are isolated in-patient units for older people who have mental health problems at Lytham and Fleetwood hospitals.
"Providing this type of service in these settings is no longer considered to be the best practice."
The changes would see fewer patients sharing wards and more focus on dignity and privacy – creating single sex wards.
Members of the public are now being asked for their views on the plans, which would not be put in place for at least five years.
People have until July 14 to say what they think.
A booklet can be obtained by ringing (01282) 607047.
To express views, write to: County Coun Tim Ormrod at Lancashire County Council Health Scrutiny Office, Christchurch Precinct, County Hall, PR1 8XJ or by emailing tim.ormrod@cc.lancscc.gov.uk.
emma.harris@blackpoolgazette.co.uk