A search to find Britain's best, perhaps unknown, portrait artist has been launched, with a £10,000 commission to paint author Hilary Mantel as first prize.

Joan Bakewell and Frank Skinner will present the Sky Arts series, and judges include the Royal Academy's director of exhibitions, Kathleen Soriano.

Artists aged 16 and over, amateur or professional, have been invited to apply. A series of roadshows will be held in Dublin, Cardiff, Glasgow and London over the summer.

"What I like about this is that it is non-elitist," said Bakewell, who sits in the House of Lords and regularly speaks on the arts. "It really is important that people don't feel that art is for posh people who have been to art school.

"I see this as a democratic way of looking at the arts, rather than any kind of snooty judgments being passed, and everyone who comes along to the roadshows will get advice."

Bakewell jumped at the chance to present the series. "Jobs on television for older women don't come very often, so when I was asked to do this I thought 'absolutely', plus it is in my neck of the woods."

She is joined by Skinner, a visual arts fan who says he has been keen to make a fine arts TV programme for some time. He is looking for diversity, adding that there is a kind of portraiture in vogue that you often see at the BP Portrait prize exhibition – "that slightly smoky photograph look".

Skinner said someone once painted his portrait on a watermelon and "it was a really good likeness; it was brilliant".

The comedian hopes a non-professional will win, someone that "even their friends might not know they do art. I suppose I'd be a bit sad if it is a very established, successful artist who won it."

As well as Soriano, judges will include the portrait artist Tai-Shan Schierenberg and Kate Bryan, head of contemporary art at the Fine Art Society.

Four finalists will compete in the closing stages, producing a portrait of a public figure. For the grand finale their work will be displayed at the National Portrait Gallery and its director, Sandy Nairne, will help choose the overall winner.

The overall winner will be commissioned to paint Mantel for a portrait that will be shown at the British Library and become part of its permanent art collection.