Managers at a Long Ashton quarry are applying for permission to continue quarrying at the site for a further eight years.

Tarmac, which owns Durnford Quarry, had initially planned to stop quarrying at the site at Longwood Lane in 2012.

But a downturn in the building trade due to the recession and a greater use of recycled stone, has meant the company, which employs 20 people at the site, still has limestone which it needs to take out.

Tarmac chiefs estimate it will take a further eight years for the remaining three million tonnes of stone to be extracted and are gearing up to submit a planning application to North Somerset Council for permission to extend its extraction rights until 2020.

Once the quarry closes, work will start on restoring it with the quarry voids being filled in with aggregates, clays and sub soils.

Bosses say no hazardous materials or household waste will be used to fill the holes.

Stone has been extracted from the quarry since the late 1800s and Tarmac took over the site in 2000.

The Clifton Down carboniferous limestone extracted from the quarry is used to produce aggregates, concrete and asphalt which is mainly supplied for construction projects including Bristol's Cabot Circus shopping development as well as houses, roads, hospitals, schools and other development schemes in the area.

Discussions are now taking place with bosses at the neighbouring Ashton Court Estate about how the quarry can be restored for future public use.

The initial vision was to retain the steep slopes and have ponds at the base but there are safety concerns about the idea.

Now plans include partially infilling the quarry to leave the space with a variety of uses.

The landform would see part of the quarry face exposed in an amphitheatre-type setting, which could be used for outdoor concerts and events.

The restoration of the site is expected to take until 2030 and when complete, it will be handed over to the Ashton Court Estate.

A public consultation has been launched to gather local residents' views on continuing to quarry at the site until 2020.

Local people are also being asked how they would like to see the site restored.

A spokesman for Tarmac said: "This has long been an important, strategic resource for the region, but we are looking towards the end of mineral extraction at Durnford.

"The economic climate and the downturn in the building trade has resulted in a lower volume of stone being extracted and we need a little longer to remove the already agreed levels of aggregate.

"While we are taking the stone out, we will be working at the same time to progressively restore the site.

"The full restoration programme will take until 2030.

"We are keen to leave the quarry as a useable asset and want people to have their say on its future."

Anyone wanting more information or to register their views on the application can email durnford.quarry@tarmac.co.uk or log onto www.tarmac.co.uk/durnford.