LONDON - A painting by former British Prime Minister Sir Winston Churchill is set to be put up for auction, reported The Telegraph.

The piece, called The Goldfish Pool At Chartwell, has never been exhibited before, and is expected to fetch up to £80,000 (S$143,748) in Sotheby's modern and post-war British art sale in London on Nov 21.

Sir Churchill, who was born in 1874 and died at the age of 90, painted about 544 pieces after taking up the hobby in the 1920s.

Painted shortly before he died in 1965, The Goldfish Pool At Chartwell - his final work - depicts the goldfish pond at his Chartwell home near the town of Westerham, Kent.

The art piece belonged to Sergeant Edmund Murray's family. Sergeant Murray served under Sir Churchill for the last 15 years of his life.

As the former statesman was overcome by ill health in the years leading up to his death, it was Sergeant Murray who set up his easel and brushes for the work.

"They've had it for a long time and they feel the time is right for someone else to enjoy it," explained Sotheby's modern and post-war British art department head Frances Christie.

She added that the goldfish pond was "the most special place in the world" for Sir Churchill, looking out over "the most incredible landscape".

"And for this great statesman, who takes a lot of credit for winning the Second World War, it is that perfect corner... that is forever England."

In 2014, a larger painting of the goldfish pond by Sir Churchill was sold for £1.8 million.

It had been owned by his daughter Mary.

None of his works were sold when he was still alive.