Sainsbury's has recreated one of the most famous moments from the First World War in its 2014 Christmas advert in partnership with armed forces charity the Royal British Legion.

The ad is a "creative interpretation" of Christmas Day 1914 when British and German soldiers laid down their weapons and met on neutral territory to share greetings, treats, mementoes and even a game of football.

Sainsbury's reconstructed the trench scenes with the help of a war historian to celebrate the supermarket's 20 years of support for the Royal British Legion, which runs the annual poppy campaign.

The ad follows a British soldier as he hears enemy troops singing Silent Night in German and ventures into "no man's land" before soldiers from both sides join him and shake hands.

He shares a moment of friendship with a young German soldier and, as the truce ends and they return to their trenches, the German is moved to discover that his British friend has hidden the gift of a chocolate bar in his pocket.

Shoppers can help to raise extra money for the Royal British Legion after Armistice Day this year by buying the chocolate bar featured in the advert from Sainsbury's stores, with the profits going to charity.

The tribute follows the exhibition of thousands of ceramic poppies in the moat of the Tower of London to commemorate 100 years since the start of the Great War, which has drawn millions of visitors.

Charles Byrne, director of fundraising for the Royal British Legion, said: "We're very proud of our 20-year partnership with Sainsbury's and this campaign is particularly important.

"One hundred years on from the 1914 Christmas truce, the campaign remembers the fallen, while helping to raise vital funds to support the future of living."

Mark Given, head of brand communications at Sainsbury's, said: "This year, we wanted to reflect that theme of sharing in our Christmas campaign through the lens of one of the most extraordinary moments of sharing in modern history when, on Christmas Day 1914, British and German soldiers laid down their arms, and came together on neutral territory to share stories, mementoes and even a game of football.

"The Christmas truce is an emotive and cherished story in our history that is especially poignant in this First World War centenary year. That's why we have worked together closely with the Legion to ensure we bring this moment to life with authenticity and respect.

"We know many of our customers feel as passionately about the incredible work of the Legion as we do. We hope our campaign will raise awareness and funds for the Legion and inspire our customers to share a memorable Christmas with family and friends."