Grangemouth has been earmarked as one of 13 potential sites for the mass-manufacture of explosives as the UK government steps up its defence strategy.

Ayrshire and Dumfriesshire have also been shortlisted for the factories which are likely to produce high explosives, rocket propellants and ignition systems at scale for use on the front line.

Defence Secretary John Healey will announce the plan in a speech this morning when he will say that the munitions facilities will boost Britain’s preparedness for war and ensure no return to the “hollowed out and underfunded” military of the past.

The defence industry has been invited to submit proposals to produce the explosives, which include military pyrotechnics.

According to the Ministry of Defence, construction of the first of the sites is expected to begin next year.

The 13 counties that could be home to the facilities are Cumbria, Dumfriesshire, Ayrshire, Shropshire, Cheshire, Derbyshire, Essex, Worcestershire, Hampshire, Pembrokeshire and Stirlingshire.