Jim Murphy is "trying to pick a fight" with Labour bosses in London with his plans to use cash raised from a mansions tax to fund 1,000 extra nurses north of the border, his Tory rival Ruth Davidson claimed.

Earlier this week the Scottish Labour leader announced he would use cash from the party's planned levy on homes worth more than £2 million to fund the additional NHS staff.

But Mr Murphy has come under attack, including from within his own party, for the move.

Labour left-winger Diane Abbot hit out yesterday, saying: ''He just thinks he can buy Scottish votes with money expropriated from London.''

Dame Tessa Jowell, a former Labour cabinet minister, was also critical, arguing that the UK capital could not "simply act as the cash cow for the rest of the UK''.

Conservative Mayor of London Boris Johnson said Mr Murphy wants to "mug"' people in the South East to ''bribe'' voters in Scotland into backing Labour rather than the SNP.

And today, Ms Davidson claimed Mr Murphy's proposal "isn't about nurses and it isn't about health", claiming it is about him "wanting to try to be the big man up here and pick a fight".

Mr Murphy's predecessor Johann Lamont stood down suddenly last year, accusing Labour leaders in London of treating Scotland like a "branch office".

Ms Davidson told BBC Radio Scotland's Good Morning Scotland programme that Mr Murphy is "using the health service as a political football and as a cynical ploy to try and boost his pro-Scottish ratings up here".

She said: "This isn't about nurses and it isn't about health, it's about the fact that his predecessor left office saying (Labour leader) Ed Miliband treated Scotland as a branch office, and he's wanting to try to be the big man up here and pick a fight.

"I think Boris Johnson, quite rightly as the Mayor of London, is looking out for people in London, which is overwhelmingly where a mansion tax would strike.

"It's absolutely right and proper for the Mayor of London to stand up for people in London, but everybody across the UK understands that as part of the UK a person who pays tax into the system in Kirkcaldy helps support pensioners take money out of the system in Carlisle and vice versa, that's what being part of one country is."

A Scottish Labour spokesman said: "If Ruth Davidson wanted to do the best for Scotland she'd be supporting Ed Miliband's mansion tax that will deliver 1,000 extra nurses to Scotland, Ed's Living Wage plan that'll give a pay rise to hundreds of thousands of Scots and Ed's energy price freeze.

"The problem for Ruth is that Scots voters want these policies and they want to send David Cameron's Tories packing."

First Minister Nicola Sturgeon described Labour's nursing pledge as "a rather silly attempt to get one over on the SNP" without any serious assessment of what the NHS needs.

Dr Margaret McGuire, nurse director at NHS Tayside, called on Labour to reveal more detail about its nursing plans, insisting any healthcare policy must consider the impact on the whole NHS team rather than focussing on one element.

Speaking on a visit to Dundee's Ninewells Hospital, Ms Sturgeon said: "Labour's pledge on nurses has got nothing to do with the health service, it's a rather silly attempt to get one over on the SNP.

"It's a pledge to have 1,000 more nurses over and above whatever the number of nurses is, so it's not borne out of any serious assessment of what the health service needs.

"My job and my priority is to keep supporting the health service day in and day out.

"There's 1,700 more nurses working in the NHS today than there were when the SNP took over from Labour in 2007.

"So we will be judged on our commitment to the health service and the health services' performance, which although it is always under challenge as an organisation, and particularly over the winter we see some particular challenges just now, our job is to support the front-line staff in the health service with the first class and fantastic job that they do."

Dr McGuire said: "Saying it's 1,000 nurses - it depends on what they're needed for and what the areas will be.

"It's like everything, I would need to look and see what the detail of it would be.

"It's important that we consider nursing but I think we need to consider in all of this the whole multi-professional team.

"The days are gone when we should just have silo working.

"I think that nursing is really important and pivotal to what we do, but we work as part of a team and every single person who works as part of the community - whether it's the cleaners in the hospital, the people that make the meals, the nurses, doctors, AHPs (allied health professionals), all our lab people - they're all very important.

"I think it's going to be important to see what Labour actually mean by that, because until you see the detail it's very difficult to know."