A fire on Marsden Moor in west Yorkshire, which has now affected 15 square kilometres of moorland, is likely to have been started by a barbecue, say landowners the National Trust.

The blaze spread quickly in the dry conditions, and despite firefighting efforts it is now estimated to have covered over 15km2 (1500 hectares).

"[This is] the most significant fire in recent years on Marsden Moor" say the National Trust.

"From where it started on Sunday at Eastergate, it spread across Close Moss and has since headed west towards Castle Shaw (united utilities land). On Monday evening the fire jumped across the A640 towards Readycon Dean Reservoir, but crews fought this breakout back to the road."

"Crews, staff and volunteers remain on site on Tuesday, and will keep up efforts to contain the fire today, in continued warm, dry weather. The rain forecast tomorrow should help the fire crews' efforts, and bring much needed moisture to the moorland after a prolonged dry spell."

Much of the moor is designated as a Site of Special Scientific Interest, a Special Protection Area and Special Area of Conservation, due to the ground nesting bird population and blanket bog habitat.

"It's likely that the biggest loss of wildlife will be nesting birds such as curlew, and mountain hares that inhabit this area of the moorland" say National Trust rangers.

The National Trust has been working in partnership with Moors for the Future and Yorkshire Water to re-wet Marsden Moor, which helps reduce the risk of wildfires and reduces downstream flooding. However, it only takes some warm weather, and one idiot with a barbecue, to undo years of work.

Ten fire crews are on site from West Yorkshire, Greater Manchester, Cumbria and Merseyside. 10 water pumps, a helicopter and a specialist high volume pump have been in use, taking water from nearby reservoirs to the fire. Holme Valley mountain rescue team and trained National Trust Rangers and volunteers are also currently assisting in beating down flames.

The National Trust are urging the public to be more alert to fire risk: "It's likely that a barbecue started the blaze... At present it is estimated that an investment of more than £200,000 in restoring this special habitat has been lost."

"Please help us protect the moors and wildlife by calling the fire brigade immediately if you spot any signs of fire. We need our visitors' help to prevent the risk of fire across the countryside that we care for, particularly when we experience prolonged periods of dry weather or are in drought conditions."

"People can make all the difference in limiting this risk by just following simple measures included in the countryside code such as ensuring they take home any litter, making sure any lit cigarettes are properly extinguished and disposed of responsibly, to never light fires and only use barbecues in authorised areas."