Roseanna Cunningham

Ms Cunningham, who joined the Faculty of Advocates in 1990 and became a non-practising member in 2002, has served as an MP and later MSP in Perth and Kinross since 1995. She has held three cabinet positions.

In a statement, she said: “It has been a massive honour to have represented my constituents in both Westminster and the Scottish Parliament for the past 25 years and to have been able to serve my country as a cabinet secretary in the Scottish government.

“I have always been hugely grateful to all who have put their faith in me.”

She added: “After a quarter of a century as an elected politician, and with another election fast approaching, I have had to do some hard thinking.

“By the time of the next election I will be less than two months away from my 70th birthday and, further, by the end of that parliamentary term I would be nearly 75. This year, of all years, has made age a rather more relevant factor than it may otherwise have been.

“I have, accordingly, taken the very difficult decision to inform my local constituency association that I will not be seeking nomination as an SNP candidate for the 2021 Scottish Parliament elections.”