THE mayor of a city dubbed "Britain's sinkhole capital" has spoken of major concerns over the collapses as work gets underway to fill a crater which appeared last month.

Mayor of Ripon Councillor Adrian Morgan said it was "heartbreaking" to see properties in the city demolished as contractors began removing unstable buildings in Magdalens Road, where numerous houses were evacuated when a 66ft-wide and 30ft-deep sinkhole opened up on November 9.

Such was the speed of the collapse, that one resident was left clinging to a washing line pole to avoid falling in the hole.

It is understood contractors are set to fill the sinkhole with concrete, while Yorkshire Water is working to replace damaged sewerage pipes, which will see some of the evacuated residents able to return to their homes before Christmas.

Geological engineers said the sinkhole appeared after gypsum, upon which much of the city is built, dissolved due to deluges of rain, creating an underground cavern.

It is believed catastrophic collapses will become more regular in the city due to climate change.

Cllr Morgan said concerns had been raised over whether the excavation of gravel from the River Ure, which runs through the city, had increased underground stream flows in the area.

He said action, such as worked proposed by Stokesley-based firm Geoinvestigate to pinpoint areas in Ripon most at risk of a collapse using an ultra-thin drill, was needed.

Cllr Morgan said: "The collapse last month was the second in two years in Ripon. We are very concerned about the situation.

"Anything that would anticipate another collapse would be welcome. If anybody could determine the true condition of the ground we would be very grateful."