THE row over Scottish Tory double-jobbing has flared up again after party leader Ruth Davidson pocketed £20,000 for a book on female leaders and pop stars.

Davidson, who earns over £60,000 as an MSP, has now declared extra income of around £25,000 following appearances on TV shows such as the Great British Bake Off and Have I Got New For You.

Scottish Labour MSP Mark Griffin said: “Ruth Davidson needs to decide if she wants to be a celebrity or a politician. She has a well-paid full-time job to represent constituents in Edinburgh, many of whom will earn less than £20,000 for their only job – let alone their second job."

The Conservatives replaced Labour last year as Holyrood’s largest opposition party and Davidson leads the charge against the SNP Government at First Minister’s Questions.

However, the lucrative outside interests enjoyed by some of the party’s MSPs has been a source of criticism.

Party justice spokesman Douglas Ross receives up to £40,000 a year as a referee and has missed Holyrood business due to his second job.

Professor Adam Tomkins declares up to £35,000 a year for teaching at Glasgow University, a stint that takes up one and a half days a week.

Central Scotland MSP Graham Simpson receives up to £20,000 a year in remuneration for his duties as a local councillor, a sum that includes salary and the value of a mobile phone and tablet.

Newly-updated Holyrood records reveal that Davidson, who is party leader and a constituency MSP, is also landing a sizeable sum in outside income.

It emerged recently that publisher Hodder & Stoughton had commissioned Davidson to write a book about the life lessons learned by the world’s most powerful women.

Davidson, who fought the last election promising to hold the SNP to account, will talk to women ranging from world leaders to pop stars and corporate chief executives.

She said at the time: “This book is for every daughter, every mother, every aunt and every niece. It tracks the great societal shifts that have brought us to where we are as well as the individuals who have helped nudge us another fraction towards the tipping point.”

Her party initially declined to say how much she would be getting paid for the book, but her register of interest makes clear she has received a £20,500 advance.

The register added: “I expect to spend 20 hours per month doing this.”

Her declaration also stated that she was commissioned to write three columns for The Daily Telegraph at £500 a time.

A guest appearance on the BBC’s Have I Got News For You netted her another £1,500, which excluded one night’s accommodation at a further cost of £177.

In October last year, she received £2,065 for being a guest on “Great British Bake Off – An Extra Slice”. The TV production company also picked up the tab for travel and accommodation. Davidson has declared around £25,565 in outside income.

Kezia Dugdale, the Scottish Labour leader, declares up to £8,000 a year for writing a newspaper column, but the fee is paid to charity and she receives no financial benefit.

Willie Rennie and Patrick Harvie, respectively the leaders of the Scottish Liberal Democrats and the Scottish Greens, declare no outside remuneration.

An SNP source said: "Ruth leads a group of part-time parliamentarians and big-time business owners – and it seems she looks less interested in being a 'strong opposition' and more interested in signing book deals and doing the rounds of the game shows."

A Scottish Conservative spokesman said: "The book Ruth agreed to take on will highlight some of the great work being accomplished by women in public life. It is not unusual for public figures to take on writing projects of this nature and to receive reimbursement. Ruth has been very clear that she will be writing it in her own time."