KEZIA Dugdale has become the second candidate to stand for Scottish Labour's deputy leadership position.

The Lothians MSP wrote on Twitter yesterday that she was "delighted" and would outline her position later this week.

Her announcement came as Scottish Labour leadership candidate Jim Murphy stood down from his international development post in Ed Miliband's Shadow Cabinet.

Mr Murphy said the challenges of reforming Scottish Labour and battling to lead the party and potentially Scotland had made it difficult for him to continue in Mr Miliband's top team.

Ms Dugdale had been seen as a potential candidate for party leader but last week ruled herself out of replacing Johann Lamont.

She has received the backing of 11 MSPs and MPs so far, including Holyrood members Jackie Baillie, James Kelly and Ken Macintosh and Westminster politicians Willie Bain and Pamela Nash. Many of the group who nominated Ms Dugdale are also backing Jim Murphy for the leadership.

North Ayrshire MP Katy Clark was the first candidate to declare interest in the deputy leadership race when she announced her intention to run on Saturday.

She has already received the backing of rail union TSSA, which is also backing Neil Findlay in the leadership race.

Ms Clark, who has been an MP since 2005, said "it can't be business as usual" and that she wanted to make issues around jobs, homes and public services central to her campaign.

"The vast majority of people want a secure job, a decent home and access to good-quality public services," Ms Clark said.

"This is prevented for too many by wealth being held in the hands of a minority.

"It is unacceptable in the 21st century that people have to queue at a food bank to feed their children.

Scotland's largest trade union, Unison, has given its backing to Ms Clark's deputy leadership contest, saying that she "is on the side of working people".

Unison Scotland Labour Link chairman Gordon McKay said: "Katy Clark has a great record of campaigning on the issues that matter to Unison members in Scotland - on public services, employment rights, pensions, inequality and many other concerns."

Ms Dugdale was elected to the Scottish Parliament in 2011.