Rural bus firms have warned EU limits on drivers' hours, and the cost of the devices needed to monitor them, will disrupt journeys and cut services.
Passengers have said the threatened routes are vital lifelines
From 1 January, any buses on routes over 31 miles (50km) will be fitted with a tachograph to ensure drivers are keeping to EU driving hours limits.
Bus firms say the £1,000 cost of the device is too much, and will force them to split routes, causing disruption.
The transport workers' union said tough rules were needed to protect drivers.
Ben Colson, who runs a small bus company in Norfolk, is lobbying the government over the new rules on behalf of a number of bus companies.
He said the worst hit routes will be those that are lifelines for urban communities who want to access the surrounding countryside.
He explained that because it is only the occasional bus routes running out from the city that go over the 31-mile limit, it will not be cost effective to install the tachographs on these few buses, and bus firms are likely to discontinue the service.
As well as the installation fees, the devices cost £500 a year to re-calibrate.
One route running out of Leeds is already scheduled to be discontinued.
The bus company Arriva is stopping its weekend service from Leeds into the Yorkshire Dales because of the cost of installing the tachographs.
Passengers said many of the people who use the bus do not have cars, and without the service they will simply be unable to access the countryside.
One solution has been to stop a bus just before the 31-mile limit, and make passengers change onto a new one.
Tom Cashman, of the Transport and General Workers Union (TGWU), said it was vital for both passengers and drivers that the drivers were not forced to drive dangerously long hours.
He also said that the new rules would give drivers the right to two consecutive days off within every fortnight.
Mr Cashman said: "European hours offer the possibility of having a civilised family life.
"It's not considered unreasonable on other jobs to have a weekend off, and in this job we're not even asking for a weekend off when everyone else is off.
"We're asking for two days off so drivers can have a family life, a life off the job."
The Vehicle and Operator Services Agency (VOSA) which regulates the industry, said it was not its intention to burden firms and drivers with pointless red tape.
Both VOSA and the Department for Transport (DfT) said the spirit of the legislation is to ensure that drivers are deployed safely in a way that minimises the effects of driver fatigue.
They said the legislation does not prohibit operators using vehicles on routes that exceed 31 miles, it simply states that if operators do operate services on such routes, then they should use tachographs.