CALLS have been made for phone mast planning rules to be reviewed after a report found more than one-quarter of Scotland has no mobile coverage.

The study published yesterday, backed by the Scottish Government, warned ministers needed to ensure planning regulations were proportionate and did not unduly inhibit the roll-out of communications networks.

The recommendation was welcomed by phone operators, who complained that Scotland's planning regime was far more restrictive than England's.

The call followed extensive research showing hundreds of "not spots," or areas without mobile phone coverage.

It found 27.5% of Scotland was without basic 2G coverage, which allows calls to be made. Even bigger swathes of the country have no 3G signal, which allow smartphones to access the internet and send emails.

Among other ­recommendations, the report urges the Scottish Government to work with telecom regulator Ofcom and phone firms to set up roaming agreements across Scotland. The facility would automatically switch a phone user's network if the only coverage available was from a rival provider. It also calls for a fuller audit of so-called not spots.

The research, commissioned by the Government, was based on 17 million samples taken by ScotRail, the Scottish Ambulance Service and other surveys. Volunteers made 50,000 checks across the country to verify the data.

It revealed 2552 separate not spots, including small inner city pockets, as well as large remote rural areas.

Among the worst-served areas was Argyll & Bute, where 38.9% of the area had no 2G signal and 71.4% was without 3G coverage. Across the Highland council area 37.7% had no 2G and 69.9% no 3G signal. In Stirling, which includes rural and urban areas, 29.2% had no 2G and 47% no 3G.

Glasgow, Dundee and ­Edinburgh enjoyed the best coverage, according to the report.

However the report identified widespread not spot pockets in Scotland's two biggest cities, with one of the largest around Gartnavel Hospital in Glasgow. It said: "Contrary to traditional thinking, not spots are found frequently in the urban environment."

The report also highlighted connection difficulties for road and rail users.

Mobile coverage along country roads, even many A-roads, was a significant problem, it said.

It singled out the B709 in the Borders, saying there was no 2G or 3G signal for 90% of its 60 miles.

It said Scotland's main rail routes, such as the Glasgow-Edinburgh link, had many sections of patchy coverage "with the high probability a call will cut out more than once during the journey".

It concluded: ­"Significant improvements will be required before mobile communications in Scotland can fully meet customers' aspirations, particularly with the massive growth in use of smartphones and tablet devices."

The Government produced a report last year, Scotland's Digital Future, which said improving mobile coverage was a key ambition.

The Mobile Operators ­Association, which represents the four UK network providers, said 99.3% of the population could get a 2G signal in Scotland, compared with 99.8% in England.

But John Cooke, the MOA's executive director, welcomed the recommendation. He added: "That's important because the Scottish telecoms planning regime is far more restrictive than the corresponding system in England; that's a disincentive to investment in telecoms infrastructure."

A Scottish Government ­spokesman said: "We are working closely with the industry to improve mobile coverage across Scotland, and to address the issues identified in this report to ensure that everyone in the country benefits from world class connectivity."