Hundreds of sheep across the Bradford district could be next in line for the cull after the Government announced fresh plans to curb foot and mouth.

Agriculture minister Nick Brown told the House of Commons yesterday of a "safety first" policy of slaughtering animals where a strong risk of infection existed, such as Cumbria, in the face of 251 recorded cases of the disease by last night.

But a spokesman for the Ministry of Agriculture, Fisheries and Food (MAFF) said the policy was "flexible" and could mean sheep in other areas of outbreak, such as Bradford, could also be killed.

MAFF investigators sent from London were no closer yesterday to discovering the source of the outbreak which led to the burning of 135 cows and 7,000 chickens at Bobby Green Farm in Queensbury.

But Graham Woods, the northern regional officer, added they were investigating a possible outbreak among sheep on a farm in East Yorkshire.

He said: "The worrying aspects of the suspected case are that it is not near any other cases and is in an area with a heavy pig population."

Brian Gill, who has 800 sheep on Hope Farm in Baildon, admitted he could only hope that the infection did not spread to his flock.

He said: "I don't think anybody is safe. At the moment, touch wood, we are clear, but you just do not know if it is going to come your way.

"We've been sent leaflets by MAFF telling us what to do. We have been using disinfectant on our land and doing everything else they recommend.

"We were sent leaflets last week telling us what to look out for and how to help prevent foot and mouth. But the problem is no one's had it for 30 years so a lot of people are learning from scratch.

"The Government seems to be saying that the disease has spread through sheep at markets, but luckily I haven't bought sheep from any markets."

John Gullett, West Ridings council member for the National Farmers' Union, agreed the new culling procedures were severe but said it may be the only solution.

He said: "It is a very, very drastic measure and means possibly up to 100,000 sheep will be killed.

"It is a dreadful situation but it's difficult to see quite how else to deal with it.

"There will be farmers in Bradford who could be affected, but a lot more heading out, especially towards Keighley."