Nicola Sturgeon has named the Prime Minister she “liked best” in her time in office, but added that she had “zero respect” for another. The former SNP leader said people “often” asked her to rank the five different Conservative prime ministers she dealt with during her time as Scottish First Minister.

While she insisted she was not going to do that, Ms Sturgeon told an audience at the Boswell Book Festival in the Scottish borders: “The one I liked best, in the sense that he was just easiest to get on with was David Cameron. The one I respected most, because she took the job seriously, always on top of her brief, even though we agreed on very little politically, was Theresa May.”

She added that “Rishi Sunak, I stood down not long after he became Prime Minister”. Speaking about Liz Truss – who was in Downing Street for less than two months – Ms Sturgeon said: “I blinked and missed her.”

The former SNP leader added: Literally the only interaction we had was around the death of the late Queen, because she became prime minister and then didn’t last very long. “And fair to say the one I have zero respect for was Boris Johnson, but there you go.”

Speaking at the book festival the former first minister described herself as being a “bit of weirdo”, telling the audience she had been reading Albert Camus’s novel The Plague when Covid struck in 2020.

While she said it “sounds really grim” she added that the novel “really helped me get a sense of perspective”. Ms Sturgeon said: “I didn’t have a lot of time to read obviously, but I would read a couple of pages before going to bed.”

She added that the book, which tells the story of a city fighting a plague outbreak, “helped calm me a little bit because Covid was bad, but the plague in this novel was a lot worse”.

The former leader added: “It gave me a sense of perspective and helped me put what we were going through into a wider context.”

She went on to tell the book festival audience if she could pass one “global law” that she would make it a requirement that people in political office should read novels.

Ms Sturgeon, who is well known for her love of books, said: “I genuinely believe that that ability to put yourselves in the shoes of other people, at different times in history, from different countries, cultures, is such an important part of understanding what makes people tick.

“And if you don’t have that as a leader I don’t know that you should be in the job.” But speaking at an event to publicise her own autobiography Frankly, which was published last year, she admitted: “I don’t really like reading memoirs.”

She added that “politicians’ memoirs generally – there are some exceptions to this – tend to be very dull and turgid and a bit self-serving, rewriting history to make themselves look much better than they actually were”.

She said: “I didn’t want to do that, I wanted to write something open and frank.”

Ms Sturgeon added that writing her memoir had been “cathartic”, although she accepted the book was “subjective”, saying: “Obviously I can’t be completely objective about my own life.”