Two vintage Bentley cars that used to belong to former Watford FC owner Sir Elton John are set to fetch more than half a million pounds at auction.

The most valuable of the two cars – a 1959 Bentley S1 Continental Sport Saloon – is expected to sell for between £400,000 and £500,000 at the auction at Bonhams in London on Saturday December 2.

At the same sale, a 1960 Bentley S2 Continental Flying Spur Saloon is set to fetch between £160,000 and £190,000.

Sir Elton, who is now 70, owned the 1959 S1 Continental for 25 years, from 1976 until 2001, when it was bought by Lord Sugar.

Sir Elton once described the car as “the most beautiful car, I think, that’s ever been designed”.

It is also a comparatively rare car, as only 431 S1 Continentals were built. When Sir Elton bought his S1 Continental he had power-assisted steering, air conditioning and a modern stereo system installed.

The 1961 SI Continental is also a rarity as it is only one of 71 right-hand drive examples of this model. Sir Elton was the fourth owner of the car. He bought it in Norfolk in the 1970s and sold it in 2001.

When Sir Elton bought his 1959 S1 Continental in 1976, it was inexpensive to run a Bentley.

In 1976, a gallon of petrol – yes, a gallon, not a litre - cost seventy seven and a half pence.

At Christie’s in London on June 5, 2001, Sir Elton John sold twenty of his vintage cars - including three other Bentleys – for £1,951,725.