Scottish Government ministers have been accused of undermining one of their own key economic policies by failing to register as living wage employers.

First Minister Nicola Sturgeon yesterday launched a fresh drive to encourage employers to sign up to the voluntary scheme, saying it was an "essential feature" of her government's drive to boost the economy.

However, anti-poverty campaigners said Holyrood could do more to promote the scheme after it emerged only seven MSPs, all backbenchers, have become officially accredited living wage employers.

One of them, Labour's Neil Findlay, accused government ministers of failing to lead by example.

Living wage employers pay staff a minimum of £7.85 per hour, a rate higher than the legal minimum wage of £6.50.

Most MSPs are believed to pay their staff above the living wage level but the campaign to accredit employers says it "makes sense" for all those already paying the rate to sign up, demonstrate their commitment and help promote the scheme to others.

MSPs were asked to register a year ago when the accreditation scheme was launched.

Since then only three SNP MSPs, Graeme Dey, Linda Fabiani and Christina McKelvie; two Labour members, Mr Findlay and Drew Smith; and two Liberal Democrats, Jim Hume and Willie Rennie, have signed up.

Peter Kelly, who co-chairs the Scottish Living Wage Campaign, said: "We would be saying to any employer, if they pay the living wage they should look at becoming accredited.

"Could more MSPs sign up? Absolutely.

"As a way of demonstrating their commitment to the living wage, we would be happy to sign up more MSPs."

He added: "MSPs obviously carry a lot of weight in their local community.

"They speak to a lot of businesses and if they want to promote the living wage we are happy to accredit them."

Collectively, MSPs are a significant employer, with hundreds of researchers, administrative staff and constituency assistants working for them.

They spend a combined £9million per year on wages and national insurance contributions.

The dearth of accredited living wage employers at Holyrood emerged as Ms Sturgeon launched a scheme called the Scottish Business Pledge.

Designed to encourage "fair and progressive" employment practices, firms which sign up are required to pay the living wage and meet a number of other criteria, such as not using exploitative zero hours contracts.

In a speech in Edinburgh, Ms Sturgeon said the living wage accreditation scheme and Scottish business pledge were "essential features of what is becoming a distinctive Scottish approach to growth".

She urged businesses to sign up, arguing it would make them more productive.

Mr Findlay said: "Here is another example of rhetoric over reality.

"The First Minister and her cabinet, including the cabinet secretary for fair work are still not accredited living wage employers.

"Either they aren't paying the living wage or can't be bothered to get accreditation.

"Whichever it is they are hardly leading by example on this vital matter."

Accredited living wage employers are entitled to use an official logo on websites and advertising material and receive a plaque to place on their office wall.

More than 200 employers in Scotland have become accredited.

The living wage campaign is run by a consortium of anti-poverty groups, trades unions and charities.

Ms Sturgeon was speaking at Tynecastle, the home of Heart of Midlothian FC, which became the first employer to sign up to the new Scottish business pledge.