Former Scottish first minister Nicola Sturgeon and crime writer Val McDermid have told how books drew them together and remain the “mainstay” of their friendship, ahead of a December event in Edinburgh.

The two will discuss the joys of reading at a festive edition of In The Company Of Books, at Assembly Hall in Edinburgh on December 15, while “interrogating” guests and drinking mulled wine.

The women described their friendship as “improbable” and said that all their conversations revolve around reading.

Former journalist McDermid has sold more than 19 million books internationally and her work has been translated into more than 40 languages. She has received six honorary doctorates and is an Honorary Fellow of St Hilda’s College, Oxford.

MSP Sturgeon was the longest-serving and first woman first minister of Scotland, and represents the Glasgow Southside constituency.

After the event in Edinburgh they will host a similar one at the Glasgow International Comedy Festival.

They said: “Books are magic. Portable magic, according to Stephen King. And like magic, books build bridges. In our case, an improbable friendship between a passionate politician and Scotland’s queen of crime.

“Our love of books is what first drew us together and it remains the mainstay of that friendship.

“Every conversation we have eventually meanders round to the books we are reading, what we’ve been enjoying, what has been making us laugh or cry, or keeping us on the edge of our seats. And now we want to share the love.

“First up, festive fun at Edinburgh’s Assembly Rooms with two stellar mystery guests, then off to the Glasgow International Comedy Festival where we’ll be joined by two top names from the comedy world.

“We’ll be interrogating our guests about the books that shaped them and why they love reading. Revelations galore await as we explore the love and laughter between the covers.”

The event is part of Edinburgh’s Christmas.

A spokesperson for Unique Assembly, producers of Edinburgh’s Christmas said: “We are thrilled to have Val and Nicola bring their in-conversation event to Edinburgh’s Christmas this year.

“This is sure to be a highlight in the Christmas calendar and we invite everyone to grab a glass of mulled wine and settle in for what will be a witty, warm and insightful event.”