This is expected to have a major impact on journey options for passengers, and will affect early morning, evening and Sunday journeys in particular.
McGill's have informed the council that the changes to the current bus are necessary to reduce their financial losses, and focus their resources on improving reliability and reducing journey failures issues.
The vast majority of bus services in West Lothian are commercial, and West Lothian Council have no influence or authority over their operation. The council uses limited funding to support around 20% of local bus services, to fill gaps in the commercial bus network and help ensure local residents have access to vital services and employment opportunities.
A West Lothian Council spokesperson said: "The changes proposed by McGill's are the most significant changes to the commercial bus network for a number of years.
"We would encourage any local residents who use Eastern Scottish services to check on how it will impact on them before Monday 8 May.
"We are aware that many local residents are frustrated with the commercial bus service, as well as the challenges faced by bus operators to deliver a reliable post-pandemic bus network that meets passenger requirements within their existing resources.
"The council has no authority over the commercial bus network, and other bus operators may decide to alter their services or introduce new ones as a result of these changes. We will consider how our limited funding can be best used to support West Lothian communities going forward."
Anyone with concerns over bus services is encouraged to take them up directly with the bus operators direct in the first instance.
Residents can also contact Bus Users Scotland (BUS) with any concerns or complaints about service by emailing firstname.lastname@example.org or calling 0300 111 0001.
The Office of the Traffic Commissioner, who regulate bus services in Scotland, can also be contacted on 0300 123 9000, by email email@example.com or in writing at Level 6, The Stamp Office, 10 Waterloo Place, Edinburgh, EH1 3EG