As anyone who has come face-to-face with Ken Currie’s Three Oncologists painting in the Scottish National Portrait Gallery can confirm, he is an expert at scaring the bejesus out of viewers. At the same time, his work draws you in and imprints itself on your synapses. Once seen. Never forgotten.

Currie handles oil paint like an old master, layering an unsettling mix of foreboding and direct eye-to-eye combat into his paintings. I can think of no one else who can paint endless shades of velvety blackness like him. He’s a dab hand at a tight head too and admits that – like his hero Francis Bacon – he is fascinated by the human face.

The Glasgow-based artist also has an abiding fascination with masks, not to mention politics. The two may even be connected...

Currie’s latest work brings together all these elements while throwing in a dash of one of his all-time favourite painters, Jacques-Louis David. It also looks set to become the defining image of Thomas Muir, one of the founding fathers of Scottish democracy.

Currie’s striking new portrait, The Trials Of Thomas Muir, was unveiled last Monday at The Lillie Art Gallery in Milngavie on the 250th anniversary of Muir’s birth. Commissioned by East Dunbartonshire Leisure and Culture Trust (EDLC), it commemorates the short yet action-packed life of Muir who lived close to present-day Bishopbriggs. His family had long been associated with the community of Birdston, near Milton of Campsie.

Muir, who died at the age of 33 in 1799, is currently the subject of a year-long festival called Thomas Muir 250. A few hours after Currie’s new portrait was unveiled, Alex Salmond delivered the inaugural Thomas Muir Lecture in Edinburgh, calling for an official pardon to be granted for Muir, who was effectively stitched up by the establishment and shipped out to Australia for his efforts to secure votes for all.

The life of Thomas Muir is a gift to artists. The potted history is that this Glasgow University-trained lawyer campaigned vociferously for universal suffrage and parliamentary reform in Scotland against the backdrop of the French Revolution. Fearing similar uprisings might occur on British soil, the government clamped down on ‘troublemakers’, and Muir and several others were put on trial for sedition in Edinburgh in 1793.

Muir used the trial as a platform for his own opinions on democracy but his campaigning came at a personal cost and he was sentenced to 14 years transportation to Botany Bay in Australia. He subsequently escaped and made his way back to Europe but was almost killed when the US ship on which he escaped was attacked by British forces. Shrapnel smashed his cheekbone and his eyes, leaving a gaping maw of a wound which rendered him unrecognisable and forced him to wear a mask to cover up his injuries. Muir died in Chantilly, France, in January 1799 as a direct result of wounds sustained during his flight to freedom.

With subject matter like Muir to deal with, it is no surprise that Ken Currie was persuaded to pick up the EDLC’s gauntlet of a portrait commission. The artist was present at the unveiling of The Trials Of Thomas Muir on Monday, when there were gasps from onlookers as a white sheet fell away from the painting to reveal the stark figure of an emaciated, deathly pale Muir, naked from the waist up.

Muir’s face is cleft in two by a blacker-than-black leather mask which casts a shadow with a hint of a guillotine’s sharp hook around its edges. A single eye with a deep shadow beneath its socket stares out. On Muir’s head is a dirty bandage which Currie told me is linked in the artist’s mind to Jacques-Louis David’s famous painting, The Death Of Marat.

David’s painting depicts the death of one of French Revolution’s key figures following his assassination in his bath by a young woman masquerading as a supporter. David, a propagandist for the revolutionary government, painted Marat’s death as a noble one. In Currie’s picture, Muir is alive, but only just: a man stripped of raiment but still possessed of a quietly noble dignity.

The key factor which saw Currie accept the commission, the artist explains, was after reading up on the David connection. “The Death Of Marat is such an important painting to me, and knowing that David had met Muir and may even have painted him drew me to him as a subject. I had also being doing a lot of work relating to facial injuries and looking at the incredible portraits which Henry Tonks did dating back to the First World War. When I realised Muir had this hugely disfiguring injury, I was hooked.

“I painted several versions but this was the first and it is the one which worked because all the emotion went into it.”

The Trials Of Thomas Muir is now in the permanent collection of the Lillie Art Gallery. It can next be viewed at the Auld Kirk Museum in Kirkintilloch from October 10-31, where it will be part of an exhibition entitled Figures And Faces (www.edlc.co.uk, 0141 578 0144). An exhibition of new etchings and monotypes by Ken Currie is at Glasgow Print Studio from September 5-October 18 (www.glasgowprintstudio.co.uk, 0141 552 0704)