Nicola Sturgeon will reunite with Alex Salmond on the election campaign trail today, as Jim Murphy makes his case for Labour in Glasgow.

The SNP leader will join her former boss in Inverurie, in the Gordon constituency.

Mr Salmond is standing for election in the seat currently held by the Liberal Democrats.

After a week of campaigning across the country, and a much-praised performance in the second televised UK leaders debate, Ms Sturgeon and Mr Salmond will seek to show that the SNP is the only party which represents all parts of Scotland.

Meanwhile, Mr Murphy will be in Glasgow city centre, with a message about the choice facing voters on May 7.

The Labour leader will argue that his party can offer progressive change in government, the day after he published his election manifesto in the city.

He will say: "In just 19 days time the people of Scotland face a simple choice. They can vote to change Scotland and the UK forever with the Labour party, or austerity max with the SNP's plans for full fiscal autonomy.

"Scottish Labour wants working class and middle class families to get a break after years of real pressure, and in too many cases, real pain.

"We have a costed plan, a positive programme based on Labour values and the people's priorities.

"We will reinforce our NHS with 1,000 more nurses and 500 more GPs. We will support all our young people to make the most of their lives, with a package of support for everyone, whether they are in work, at university or looking for a job.

"And our progressive taxes will make sure that those who have the most, pay their fair share towards rebuilding our economy."

He will add: "Scotland can have austerity max or elect a real progressive alliance. A coalition of Labour MPs elected in cities of north England, in the industrial heartlands of the Midlands, in the valleys of Wales, in inner city London, and the cities, towns and villages of Scotland, to change our country forever."

Scottish Conservative leader Ruth Davidson will also be in the north east as she joins party activists in Aberdeen city centre at a street stall to talk to voters.

And Liberal Democrat Jo Swinson will highlight plans to boost opportunities for young people through increased support for mental health services on the campaign trail in Bearsden, East Dunbartonshire.

Scotland could find itself completely outside any government if it votes overwhelmingly for the SNP at the election, deputy Lib Dem leader Sir Malcolm Bruce has said.

Mr Salmond is battling to take Sir Malcolm's seat in Gordon, north-east Scotland, with the Lib Dem standing down after 32 years in Parliament.

Sir Malcolm claimed that people were waking up to the fact that a clean sweep of SNP MPs could give them no representation in government and so were thinking about voting tactically.

He told BBC Radio 4's Today programme: "I am meeting people who voted Yes, who are not voting for the SNP and feel it's maybe gone too far and we should move on.

"Secondly there wasn't a uniform vote across Scotland, there were very substantial variations.

"Here we are in the north east of Scotland, it was overwhelmingly against independence, certainly well over 60%.

"Therefore you cannot assume that the SNP will actually get enough votes automatically to hold or win seats in the north east or other parts of Scotland.

"We are finding that people are voting tactically because if you take these polls all the way through, Scotland could effectively put itself out of reach of being part of any government because we have elected nobody of the governing party, whatever it is.

"That's not good for Scotland."

Sir Malcolm also argued that unlike the SNP, the Lib Dems were likely to be in coalition after May 7, and so would have far more success in delivering policies than the Nats.

He said: "Our argument is the system is not delivering a majority to any party, actually a stable government requires a coalition, not confidence and supply, and actually the junior partner can deliver policies if it's in government in a way that it can't from opposition."

On her visit to Aberdeen, Ms Davidson called for more apprenticeships for the north east's offshore sector.

It follows a survey earlier this year which identified a shortage of skills as the greatest challenge facing the industry in the coming years.

The Scottish Conservatives' manifesto contains a pledge to introduce an extra 10,000 apprenticeships on top of the SNP's target by the end of the decade.

Ms Davidson said: "I refuse to live in a country where we deem it acceptable for a young person to leave school and walk straight to the job queue. If just one young person has left education without the skills they need for a job, then we have failed.

"The recent Bank of Scotland Oil and Gas survey was quite clear that concerns about a shortage of skills in the sector are growing. Many firms consider this the biggest challenge they face.

"Our universities are doing more to address this, but we can do more. That's why the Scottish Conservatives are backing an extra 10,000 apprentices by the end of the decade.

"That's double the rate of increase proposed by the SNP and reflects the urgency of the situation we face.

"I'd like to see many of these new apprenticeships designed for the north east's oil and gas sector - because we know that there is still a great future for thousands of Scots in our energy business.

"The more Scottish Conservative MPs we return in May, the more we can drive forward our positive plan for a growing economy and a skilled workforce."