A Christmas part in an air-raid shelter The Chislehurst Caves are turned back into an air raid shelter The Open University/BBC co-production which took three brave volunteers back to experience agricultural life under fire returns for a Christmas special, as Ruth and Peter prepare for a 1944 Christmas.

1944 saw the sixth Christmas at war, and shortages were biting deeper than ever. Added to this Britain’s cities were in the grip of the worst German attacks since the Blitz of 1940. Unmanned flying bombs – the dreaded V1 ‘Doodlebugs’ and V2 rockets - rained down, stretching morale and services to breaking point.

Having been set the target of doubling home-grown food production by the government, Britain’s farmers had already ploughed up six and a half million additional acres in the drive for additional crops (an area equivalent in size to the whole of Wales!)

Now, in addition to maintaining food production, it fell to Britain’s farmers to come to aid of the nation’s urban dispossessed in their hour of need.

Many rural women joined the one million-strong Women’s Voluntary Service to provide food, drink and gifts to lift in the spirits – especially at Christmas. Ruth finds out how the WVS operated the government’s National Pie Scheme.

Beer was seen as so essential to the nation’s morale that it was never rationed – but a vital ingredient, barley, was in short supply so substitutes were needed. Peter calls upon rural crafts expert, Colin Richards, to brew some improvised Potato Beer for Christmas.

Meanwhile Ruth comes up with innovative presents for children, and ingenious festive decorations made from scraps.

After enjoying a Christmas church service for the community at Manor Farm - including German prisoners-of-war who, along with Italian POWs, accounted for one in five of the farming labour force in Britain by Christmas 1944 and had become surprisingly well-integrated into some rural communities.

Following in the footsteps of many wartime rural farmers, Peter and Ruth transport their gifts, food and beer on a vintage wartime steam train to Chislehurst Caves - 10 miles outside London - where they discover what Christmas was like for some of the 15,000 people who sheltered in the caves.

Following recipes and guidelines issues by the government and the WVS, Ruth cooks an improvised Christmas meal, relying chiefly on rabbit and a glut of carrots from the farm.

And the Salvation Army bring musical cheer to the occasion as the team reflect on the impact of what was to be the last Christmas of the Second World War.

Wartime Farm: Christmas Special will be first broadcast on December 18th, 2012 at 9.00pm. For further broadcast details, and to watch online where available, please visit bbc.co.uk.