Extra supplies are also being built up at bases in the UK to reduce the risk of the armed forces running short and being unable to operate if it suddenly becomes much harder to import and export day-to-day goods after 29 March.

Military chiefs have spent at least £23million on what is being described as "forward-purchased" goods.

The move is part of contingency planning by the government - codenamed Operation Yellowhammer - to reduce disruption if Britain departs from the European Union without an agreement, according to three defence sources.

Operation Yellowhammer is aimed at keeping sailors, soldiers and pilots fed and equipped should the lack of a deal with the EU after March 29 lead to shortages of key items, the channel reported.

29-01-19 PANORAMAdailyGIBRALTAR