Sketches of Winston Churchill drawn on the back of a menu by Sir John Elliott during a dinner at Mansion House in 1954. Photo: Andy Newman/PA Wire

A series of absent-minded doodles of Sir Winston Churchill sketched on the back of a menu are expected to fetch hundreds of pounds at auction.

Auctioneers say it is unlikely the artist, railways manager Sir John Elliott, would have been aware that the pencil drawings made during a long dinner attended by the former prime minister at London’s Mansion House would have any value decades later.

But his 1954 portrayal, thought to have been scribbled on the nearest available menu as those gathered listened to after dinner speeches, is expected to become the latest in a long-line of Churchill artefacts to sell at auction.

Sarah Prior, of Keys auction house in Aylsham, Norfolk, said the drawings, along with a half-smoked cigar snatched from Churchill’s table, were likely to generate a great deal of interest when they go up for auction today.

She added: “Sir Winston was probably completely unaware of the fact he was being sketched – that’s part of the charm as it captures him in a candid way.

“Sir John died in 1988 but it wasn’t until now that his family wondered if these items may have some value to somebody else. We have seen Churchill cigars on auction before but this is the first time I’m aware of that drawings of this kind have been offered.

Sir Winston was probably completely unaware of the fact he was being sketched

“There remains a great deal of interest in Churchill artefacts of all kinds but the ones of real value are those that can be linked to key dates in his career.”

In 2010 a half-smoked cigar belonging to Churchill sold for £4,500 at the same auction house.