Three bus routes in North Somerset face being scrapped after 9 October as Covid-support funds are withdrawn.
North Somerset Council has warned the X2, X5 and 126 are no longer commercially viable and risk closure.
Although it recently received government funding to boost services, the council has been told this cannot be used to fund unsustainable routes.
"Without additional funding, we can't afford to replace current routes," said councillor Steve Hogg.
The three services at risk of closure serve the following places:
- X2 Bristol to Yatton, via Long Ashton, Flax Bourton, Backwell, Cleeve & Claverham.
- X5 Weston-super-Mare to Bristol, via Worle, Clevedon & Portishead.
- 126 Weston-super-Mare to Wells, via Locking, Sandford, Axbridge, Draycott & Westbury-sub-Mendip.
The funding gap comes as central government relief that kept services going during the Covid-19 pandemic is being withdrawn.
Operators are struggling with ongoing shortages of drivers, and passenger numbers which have not fully returned to pre-pandemic levels.
Mr Hogg, Independent, said the council was "committed to lobbying government and working with bus operators to explore every avenue to maintain services".
Wells MP James Heappey said the 126 route was a "lifeline" for Somerset residents, linking villages without doctor's surgeries to those with them.
"In Somerset there's only a handful of bus routes remaining," he said.
"The fact the 126 route isn't used by dozens of people every day shouldn't hide the fact that it is a vital lifeline.
"If local councils think bus routes are necessary then they have it in their gift to step in."
First West of England said: "No decisions have been made but we must adapt our networks to match the post-pandemic demand for services.
"The majority of our networks will be retained, and we are committed to working with local authorities to provide notice of any changes to allow them to support alternative arrangements."