Some of the toughest anti foot-and-mouth measures so far have been launched across a huge swathe of North Yorkshire

With foot-and-mouth marching down the Vale of York, the area was turned into "a biosecurity fortress" last night in a desperate attempt to prevent the county's pig industry being wiped out.

It will see officials from the Department for the Environment, Food and Rural Affairs (Defra) riding shotgun on all milk tankers and many other vehicles in a 900-square mile area.

All livestock movements will be banned with the exception of those under licence for slaughter, either for human consumption or under the livestock welfare disposal scheme.

Every vehicle that goes on or off the 1,200 farms in the area will have to be thoroughly cleansed and disinfected each and every time.

Fifteen teams of Defra, police and trading standards officers will patrol the area carrying out roadside checks to make sure the measures are being adhered to.

Those that fail to make the standard will automatically be sent to one of six cleansing and disinfectant stations more of which could be established should it become necessary.

And repeat offenders could find themselves facing fines of up to £5,000.

The bio-security intensification area is centred on Thirsk and stretches as far as Northallerton, York, Harrogate and Malton. It is surrounded by a buffer-zone, where livestock movements in or out are banned, except for licensed slaughter.

"These measures are going to be an enormous blow for the farmers but they needed to be taken," said a spokesman for the National Farmrs' Union (NFU) in the area last night.

"They are going to create a massive amount of headaches, particularly during harvest for mixed farms.

"But the short-term pain is necessary if there is going to be long-term gain."

In the past three weeks, foot-and-mouth has been confirmed at 12 farms in the Thirsk area regarded as the gateway to the massive pig industry of the Vale of York and East Yorkshire.

So far, cases in the area have been restricted to cattle and sheep but with the disease being thousands of times more virulent in pigs, the drastic measures are being taken to stop it in its tracks.

Over the weekend, about 8,100 pigs on a farm near Thirsk were slaughtered after a suspected "dangerous contact", although no signs of the disease were found.

The new measures also include:

* Specific licences needed for silage vehicles to go on or off farms

* Special licences needed to discharge slurry by jet or spray

* Clothing and boots worn while handling livestock must be left on the premises

* Footbaths to be maintained at every exit to all farms.

Read more about the foot-and-mouth crisis here.