The Dublin-born artist created the canvas, known as “Landscape with Pope/Dictator”, in 1946 while living in Monaco.

It depicts a blurred, open-mouthed figure in a biretta, a traditional cap worn by Catholic clergy and wearing a politician’s usual attire of a shirt and tie. A microphone stands in front of him, and beneath are flowers.

Art gallery Gagosian, which is showing the work in its London Davies Street premises, said it was “Bacon’s first treatment of the papal image”.

“Here you’ve got this hybrid figure – a papal clerical figure but, at the same time, dressed in an ordinary secular suit and tie,” Richard Calvocoressi, director and curator at the Gagosian gallery, said.

“Fusing these two figures of authority – on the one hand the pope, on the other the dictator – is something Bacon pursued for 20 years, often coming back to this idea.”

The painting was recently discovered when British art historian and curator Martin Harrison compiled a catalogue of Bacon’s work. The listing was published in 2016.

“It’s never been in an exhibition. It went into a private collection in Italy in 1967 and really, this is its first public appearance since then,” Calvocoressi said.

The painting is on show until April 23.