The future of the prestige laboratory is seen as a test of the Government’s resolve to defeat what the Home Office calls “the animal extremists’ reign of terror”. Private assurances were given to leading researchers by ministers last week shortly before they announced a range of tough new measures aimed at violent militants.

One scientist said “We were left in no doubt that the military will be used if that is what it takes to get the Oxford project completed. Whitehall recognises if this facility is bullied and intimidated out of business then research companies will abandon Britain in their droves. We were promised protection will be given to all those involved with Oxford at all cost.”

Contingency plans have been drawn up to protect suppliers delivering vital components to the construction site, and thwarting militants’ plans to sabotage the building.

At least £1 billion worth of research programmes have been lost by Britain in the past two years, and leading companies say that they are considering shifting work to their laboratories overseas if the campaign of intimidation continues.