Telecom providers need to up their game in Dorset and improve telephone coverage to the many places which have a poor or non-existent connection, according to some councillors.

Dorset councillors heard that, although the commercial providers promise to make improvements, they often change their plans and nothing happens.

Cllr Simon Gibson said he knew of one road in the Verwood area where all surrounding households now had access to good signal, but despite promises by a company to "plug the gap", it had not happened and, worse, the telecoms firm was now blaming the council for the failure.

"We need to be positive to move these big companies to do the right thing," he said.

"There is a gap between what they say they will do and what they have done – and that's where the frustration is."

Another councillor from the area, Cllr Toni Coombs, said that she feared breaking down on some roads in the south east of the county because many had no phone signal at all.

"There are an awful lot of spots where there is no signal around Verwood. When driving, if I broke down on those roads, I would be vulnerable," she said.

Cllr Sherry Jespersen, who chairs on the council's Area Planning Committee, said there remained "a fog" over the way in which planning applications for masts were dealt with.

She said in her ward of Hill Forts and Upper Tarrants, a provider had been planning a mast within inches of garden gates in a housing estate, and in another unsuitable location, with residents apparently powerless to stop them.

"Negotiations were well advanced before any conversations were held with the landowner… and when the conversation was had it was made quite clear that they [the landowner] didn't have the power to say no, which I found strange and caused the landowner a great deal of anxiety," she said.

Cllr Jepersen said the process for a mast should be the same as for other planning applications, although the government was encouraging a process where masts were considered permitted development, without the need to go through the full planning process.

Cllr Rowland Tarr said that in Martinstown, near Dorchester, two masts had been erected side by side on the edge of an Area of Oustanding Natural Beauty, with locals claiming that one of them was not even working.

Senior council officer Matt Piles, who oversees planning, said he wished the commercial providers would engage with the council's planning and highways department much sooner when they were proposing new masts.

The report to the committee warned that Dorset overall continued to lag behind other areas in terms of connectivity – contrasting poorly with neighbouring Bournemouth, Christchurch and Poole, where there was 83 per cent gigabyte coverage – compared to Dorset's 37 per cent.

A report to councillors concluded that mobile connectivity across the county is "patchy" for all four major providers, with the risk that services will get worse, not better, when 2G and 3G services are switched off from 2025 onwards.

Much of the problems is said to be caused by the rural nature and topography of the county, making service provision less cost-effective than in urban areas.

Weymouth councillor Ryan Hope told the meeting that, despite the map which showed mobile coverage being good in his town, in the summer the influx of visitors meant that signal became much worse and people struggled to connect, no matter which network they were on.

He warned that if the situation continued, it would begin to affect the wider economy, as people were being prevented from operating as the government envisaged, with more activity taking place online and via smart phones.