Schools, hospitals and other key services in Cornwall take more than 20 minutes on average to reach on foot or public transport, figures reveal.

Council chiefs have called on the government to ringfence funding for transport networks to tackle travel times which are getting longer nationwide.

Each year the Department for Transport calculates journey times from neighbourhoods across England to eight local services by walking or on public transport.

The measure represents a typical Tuesday's travel in October, based on road networks, traffic speeds and public transport timetables.

Destinations range from job centres to GP surgeries and food shops.

In Cornwall, journey times to these sites averaged 26.5 minutes on foot or public transport in 2017, the year covered by the latest statistics – longer than the average 21.3 minutes across the south west.

This was the slowest time since the measurements began three years earlier.

Food shops were the most accessible service – with journey times averaging 12.2 minutes – followed by primary schools (12.3 minutes) and centres of employment with between 500 and 4,999 jobs (17.7 minutes).

At the other end of the scale were hospitals. Buses, trains or pounding the pavement would take you an hour to reach them.

Across England, key services can be reached within 17.8 minutes on average, either by walking or travelling on public transport.

This compares to 17 minutes when records began in 2014.

The Department for Transport attributes the longer average journeys to changes to the data used in the calculations.

Updated datasets show fewer GP surgeries but more walking routes in towns and cities, it says.

London was the region with the shortest average travel time, at 12 minutes. This was nearly 10 minutes quicker than the south west, which had the longest.

A Local Government Association spokesman said: "The government needs to give councils long-term guaranteed infrastructure funding to deliver the improvements in our roads and public transport networks that we require.

"It should also provide ongoing investment in local bus services, which can be a lifeline for our most vulnerable residents, whether that is to go shopping, collect medication, attend doctor appointments or socialise with friends.

"Giving all councils the power to enforce moving traffic offences would also help to reduce congestion and improve journey times."

A spokesman for the Community Transport Association said cuts to commercial bus routes had driven up demand for their services.

He added: "There are numerous examples of a community transport provider stepping in to keep a service going when it has been cut by a commercial operator or a local authority for being unprofitable, despite being a lifeline to people in a rural community."