Auxiliary Units The Auxiliary Units or GHQ Auxiliary Units were specially trained , highly secret units created by the United Kingdom government during the Second World War , with the aim of resisting any eventual occupation of the United Kingdom by Nazi Germany , after a planned invasion which the Germans codenamed Operation Sea Lion . Having had the advantage of seeing the fall of several Continental nations , the United Kingdom was the only country during the war that was able to create such a resistance movement in advance of an invasion . Winston Churchill ( Prime Minister from 10 May 1940 ) initiated the units , sometimes referred to as a part of the " British Resistance Organisation " , in the early summer of 1940 . He appointed Colonel Colin Gubbins to found them . The Auxiliary Units answered to GHQ Home Forces , but were organised as if part of the local Home Guard . Gubbins , a regular British Army soldier , had acquired considerable experience and expertise in guerrilla warfare during the Allied intervention in the Russian Civil War in 1919 and in the Anglo - Irish War of 1919 - 1921 . Most recently , he had returned from Norway , where he headed the Independent Companies , the predecessors of the British Commandos . ( In November 1940 Gubbins would move to the Special Operations Executive ( SOE ) . ) Beginnings . Gubbins used several officers who had served with the Independent Companies in Norway , plus others he had known there . Units were localised on a county structure , as they would probably be fragmented and isolated from each other . Priority was given to the counties most at risk from enemy invasion , the two most vulnerable being Kent and Sussex in southeast England . The two best known officers from this period were Captain Peter Fleming of the Grenadier Guards and Captain Mike Calvert of the Royal Engineers . Fleming came from a famous banking family and was the elder brother of Ian Fleming . Calvert had recently served in the 5th Battalion , Scots Guards , which had been formed to fight as a ski - troop in Finland . Both of these men were too valuable to stay long , once the immediate threat of invasion was over , and both later served in Burma , Fleming in deception work , Calvert in the Chindits . The ' combat units ' were the " Operational Patrols " , but these were supported by Special Duty Sections , from the local civilian population . This group acted as the spotter s for the action teams . In addition , a signals structure would attempt to link the isolated bands into a national network that could act in concert , on behalf of a British government - in - exile and its representatives still in the United Kingdom . Some tales attached to the Auxiliary Units are of varying degrees of credibility . Members were supposedly vetted by a senior local police chief who was allegedly , according to sealed orders given to the Operational Patrols to be opened only in case of invasion , to be assassinated to prevent the membership of the Auxiliary Units being revealed . The Auxiliary Units were kept in being long after any immediate Nazi threat had passed and were stood down only in 1944 . Several Auxiliary Unit members later joined the Special Air Service . Many men saw action in the campaign in France in late 1944 , notably in Operation Houndsworth and Operation Bulbasket . The units ' existence did not generally become known by the public until the 1990s , though a book on the subject was published in 1968 . Special Duty Sections and Signals . The Special Duties Sections were largely recruited from the civilian population , with around 4 , 000 members . They had been trained to identify vehicles , high - ranking officers and military units , and were to gather intelligence and leave reports in dead letter drops . The reports would be collected by runners and taken to one of over 200 secret radio transmitters operated by trained civilian Signals staff . Operational Patrols . Operational Patrols consisted of between four and eight men , often farmers or landowners and usually recruited from the most able members of the Home Guard , who also needed an excellent local knowledge and the ability to live off the land . As cover , the men were allocated to " Home Guard " battalions 201 ( Scotland ) , 202 ( northern England ) , or 203 ( southern England ) and provided with Home Guard uniforms , though they were not actually Home Guard units . Around 3 , 500 such men were trained on weekend courses at Coleshill House near Highworth , Wiltshire , in the arts of guerrilla warfare including assassination , unarmed combat , demolition and sabotage . Recruits for Coleshill reported to the Highworth post office , from where the postmistress Mabel Stranks arranged for their collection . Each Patrol was a self - contained cell , expected to be self - sufficient and operationally autonomous in the case of invasion , generally operating within a 15 - mile radius . They were provided with a concealed underground Operational Base ( OB ) , usually built by the Royal Engineers in a local woodland , with a camouflaged entrance and emergency escape tunnel ; it is thought that 400 to 500 such OBs were constructed . Some Patrols had an additional concealed Observation Post . Patrols were also provided with a selection of the latest weapons including a silenced pistol or Sten Gun and Fairbairn - Sykes " commando " knives , quantities of plastic explosive , incendiary devices , and food to last for two weeks . Members anticipated being shot if they were captured , and were expected to shoot themselves first rather than be taken alive . The mission of the units was to attack invading forces from behind their own lines while conventional forces fell back to the last - ditch GHQ Line . Aircraft , fuel dump s , railway lines , and depots were high on the list of targets , as were senior German officers . Patrols secretly reconnoitred local country houses , which might be used by German officers , in preparation . Cultural references . An Auxiliary Unit arms cache features in the 1985 BBC TV series ; " Blott on the Landscape " . The Auxiliary Units feature in two UK films that imagine what would have happened if Germany had successfully invaded Britain : the 1966 film " It Happened Here " and the 2011 film " Resistance " . The Auxiliary Units feature in the BBC programme " Wartime Farm " .