An antiques dealer is hoping someone can shed light on a painting possibly created in Chelsea which depicts Margaret Thatcher addressing MPs at the dispatch box in the House of Commons.

The unfinished and unsigned painting was picked up by Daniel Hadden at a market outside of London last year and shows the Tory leader during her first few months as Prime Minister.

Art experts at the Houses of Parliament believe the painting is by Alfred Reginald Thomson, who lived in the ground floor flat Milton House, in Fernshaw Road, Chelsea.

The celebrated artist was deaf and mute and a member of the Royal Academy. He died in October 1979 aged 82, which would explain by the painting, which measures around three by four feet, is not quite complete and without a signature.

Paintings by Thomson are in high demand, with his 1948 depiction of the London Amateur Boxing Championship selling for £73,250 in 2012.

Now Mr Hadden is hoping someone can uncover the mystery behind the painting, which shows the youthful PM standing in front of Michael Heseltine and Edward Heath, and confirm if it is one of the last paintings by Thomson.

He told getwestlondon: “Parliament is very excited by this and they have a couple of other paintings by the same artist. So they’ve asked me to find out what I can.

“I know he had two children who themselves must be very old now but I’m just looking for family or friends or anyone who knew him who may remember him painting this.

!There might be some old boy who had tea with him who remembers it in his studio. This is what I’ve been asked to find out.”

Mystery surrounds chambers painting

The Sussex dealer saw the painting on a cold and wet November morning while at a market.

He has previously sold dresses belonging to Mrs Thatcher and said he knew straight away that it could be of importance.

He said: “I saw it and immediately knew it could be an important piece. It looks special. I asked the person selling it where he got it from and he said it came from a house clearance in London. It was in the garage.”

One mystery surrounding the paining is that permission must be given by the Speaker of the House for an artist to paint while the Commons is in session. But there are no records showing permission in 1979.

However, Thomson was the first artist allowed inside to paint the chamber when he captured Winston Churchill, and later the House of Lords.

Mr Hadden said: “One theory is he [Thomson] did this painting from memory or sketches he had already taken down.”

In April 2015 an art gallery asked the public to help pin the exact Hammersmith location of a painting by artist Ludovic-Rodo Pissarro

Anyone who thinks they can help Daniel can email him at danielhadden@hotmail.co.uk or call 07792023938.