Labour will fight the Holyrood election with its most radical manifesto ever, Scottish leader Kezia Dugdale vowed as she branded SNP rival First Minister Nicola Sturgeon "utterly arrogant".

While polls show Labour could be overtaken by the Tories on May 5 and become the third party in the Scottish Parliament, Ms Dugdale insisted there are "no foregone conclusions" in the election.

She accused the SNP leader of having "already declared victory before any of us have cast a single vote".

Ms Dugdale told the Scottish Labour conference in Glasgow: "How utterly arrogant of her.

"We're here to tell the First Minister that there are no foregone conclusions in a democracy.

"We're here to tell her not take her power for granted. We're here to tell her not to take people for granted."

Ms Sturgeon is the "over-confident frontrunner" in the contest for the Scottish Parliament, Ms Dugdale said, but she warned the SNP leader she could be "surprised by the newcomer".

In her speech, she pledged Labour "will end austerity in Scotland".

If the party wins power at Holyrood, it will be guided by a fiscal rule that dictates there can be no tax cuts at the same time as public spending is being reduced.

This will "simply set out the path that must be followed in order to dispense with austerity and invest in our economy," Ms Dugdale argued.

She stated: "We will stand for the most powerful Scottish Parliament ever with the most radical Labour manifesto ever."

The Scottish Labour leader went on to call on voters to "make the next phase of devolution be about radicalism and responsibility".

Scots will be guaranteed a GP appointment within 48 hours, which they will be able to book online, by 2021, Labour has promised.

Ms Dugdale said: "Instead of the cuts to GPs we've seen in the last decade, our plan for the NHS will guarantee an appointment at your local surgery, which you can book online if you choose, within 48 hours."

With patients being kept in hospital once they are clinically well enough to go home because the support they need is not in place, the Scottish Labour leader also pledged a guaranteed assessment and care package within one week.

"It is a national disgrace that more than 270 Scots died last year still waiting for a care package," she told the audience, adding that care workers would also be guaranteed to be paid the living wage under her party.

Ms Dugdale said Labour offered a combination of "radical policies with financial responsibility".

She stated: "Labour will use the powers of our parliament to get serious about Scotland's housing crisis."

While the SNP has pledged to cut air passenger duty for Scots, she said Labour would help young people save towards a deposit for a new home, tackle rent rises in the private sector and "take on slum landlords to provide warm and secure homes".

She added that a new generation of council houses would be built and promised Labour would use new welfare powers coming to Holyrood to "put some decency back into the welfare state".

Labour has already said it would increase the allowance paid to carers, give a grant to youngsters who have been in care who go on to university and double the maternity grant paid to disadvantaged new mothers.

"I want a Labour government after the election," she said.

"I want as many Labour MSPs in that Parliament so that rather than arguing for change we have the power to force change.

"That's why we will be fighting for every vote, on every street, in every part of Scotland."

She told voters: "If you want a government that is less interested in taking selfies and more interested in taking on the establishment, then consider giving your first or second votes to the Labour Party."

Her party would "deliver real change" now, Ms Dugdale insisted, unlike the "distant promised land" of independence offered by the SNP.

Labour was all but wiped out in Scotland in last May's Westminster election, with the party losing 40 of the 41 seats it had won in 2010.

Ms Dugdale said that had been "the most painful election in our history" but said the party was now under new leadership.

She told the conference: "We have new candidates. And most importantly a new vision which we will take to the country."

With Scotland to get powers over income tax and some responsibility for welfare from 2017 onwards, she said May's ballot would be "the most interesting, exciting, important election we have ever faced".

In this election Scots can "see who are our leaders really are" with Ms Dugdale declaring: "I am a socialist.

"My Scotland is one where there are no foregone conclusions.

"I believe that trend is not destiny, that people aren't fated to be rich or poor, that we can choose to be better as a society."

Ms Dugdale insisted "no ifs, not buts, no fracking" in Scotland under Labour, and also promised to bring in smart ticketing for public transport, which travellers can use on buses, trains, trams and ferries.

But there was no mention in her speech for Labour UK leader Jeremy Corbyn, who did not attend the Scottish conference.

Afterwards SNP business convener Derek Mackay said: "This speech showed why a vote for the SNP is so important to keep Scotland moving forward.

"On the day the opinion polls showed Labour lagging behind the Tories these are simply empty promises from a party that openly admits it is campaigning for second place and has abandoned constituencies across the country.

"These elections really matter because they decide who will be trusted with the health service, our children's education and growing the economy. Electing an SNP government with Nicola Sturgeon as First Minister will allow us to truly transform Scotland for the better.

"By using both votes for the SNP the people of Scotland will get a government with clear plans to tackle inequality, support public services and invest in jobs. All Labour have to offer is the threat of tax hikes on low earning households.

"With Labour split from top to bottom on everything, and the Tories tearing themselves apart on Europe - only the SNP has the strength, unity and vision to keep Scotland moving forward."