A classic car enthusiast is set to raise up to £250,000 when he auctions an “unmatched” collection of Humber vehicles that have been used by royalty and celebrities across the decades.

Cars used by the Queen Mother and Edward VIII and Wallis Simpson are among the highlights of the rare collection, which also features several vehicles used in films starring top Hollywood stars.

Allan Marshall, 64, from Hull, is reluctantly selling “the best collection of Humber vehicles in the world” due to spiralling costs.

The collection of 16 vintage vehicles was started 60 years ago by Mr Marshall’s father, Reg, and has attracted visitors from across the world to the storage facility on Cleveland Street, in east Hull.

It contains a 1952 Super-Snipe MKIII that belonged to the Queen Mother, which is believed to bear marks from her fingernails on the grab handles inside the car.

The collection also features a 1930s 80bhp Snipe, found in a Northamptonshire scrapyard, which was used by Edward VIII and Wallis Simpson to help the couple drive around London in private.

Other highlights include a Humber Imperial built for George VI, who died before it could be delivered; a 1967 Imperial saloon used in the 1978 film The Big Sleep, starring Robert Mitchum; another car used in the 1965 spy thriller Operation Crossbow, starring John Mills and Sophia Loren; and cars used in a Buddy Holly film and the 2015 movie A Royal Night Out.

Mr Marshall is hoping to sell the cars as one lot and said he will only include his most precious car – a 1954 Pullman built for Baroness Rothschild and the first car bought by his father for £90 in 1960 – if a single owner buys the entire collection.

The retired potato merchant said he has used the cars – which he describes as being like his family – to take his children and grandchildren to their christenings, and revealed he had a procession of seven Humbers at his daughter’s wedding.

He said: “I don’t really want to let them go, they’re so special to me.

“It’s taken me decades to build up the best collection of Humber vehicles in the world. They’re unmatched anywhere.

“But I’m in my 60s now and I won’t be here forever.”

He added: “The time has come to let go. The costs of keeping them are too much for me now.

“My wife, Barbara, and I haven’t had a holiday for more than 40 years and if it’s a choice between my cars and my wife, there’s no contest.”

Mr Marshall’s cars are due to be sold by Hansons Auctioneers and could fetch between £200,000 and £250,000.

Rik Alexander, who is managing the sale, said: “We are absolutely bowled over by the brilliance of Allan’s Humbers.

“Every single one of them has a special story, a special place in history. The royal ones are particularly magnificent.”

The Allan Marshall Humber Car Collection Auction is due to take place on April 17, and potential purchasers are invited to contact Mr Alexander on ralexander@hansonsauctioneers.co.uk