Labour leader Jeremy Corbyn has accused the SNP of wearing an "anti-austerity badge" while pursuing policies which continue it, or could make it worse in future.
Mr Corbyn, who will be in Scotland next Thursday, said his message is "flags don't build houses".
The Labour leader was speaking on BBC One's Andrew Marr programme as the party's conference got under way in Brighton.
SNP deputy leader Stewart Hosie dismissed his comments as "the same old lines we have heard for years".
Mr Corbyn said: "Yes they (the SNP) have an austerity badge, but where is the economic strategy behind it which doesn't either continue the austerity that is happening now, or if they go for fiscal devolution is going to be even worse in Scotland because of the price of oil at the present time?"
He pointed to the SNP "privatising CalMac, also were behind the privatisation of ScotRail, also cutting college places, also privatising services, also cutting local government funding", while campaigning under an anti-austerity banner.
He added: "If you are poor in Glasgow or you are poor in Birmingham - you are poor. If you need a house in Glasgow or you need a house in London - you need a house, and so there is the class politics issue of it.
"That is the message I am taking when I am campaigning in Scotland just as much as I am campaigning anywhere else. Flags don't build houses."
Mr Corbyn said he "will not be standing alongside David Cameron" to oppose independence, but would instead be "standing alongside Kezia Dugdale and the Scottish Labour Party".
Meanwhile Scottish Labour leader Ms Dugdale will address the conference later today, telling supporters her predecessors had listened following election drubbings before but failed to act - ensuring defeat all over again.
Ms Dugdale will say: "I've watched many speeches from former Scottish leaders at this conference.
"And since 2007, they've followed a pattern. They've spoken passionately and forcefully about the problems Scotland faces... and they've pledged to listen to the Scottish people.
"I'm not here today to make another pledge to listen to people. I'm here to say: we get the message and we're going to do something about it."
Ms Dugdale faces an uphill battle to win Labour power for the first time since the SNP took the reins in coalition at Holyrood in 2007 and then as a majority government in 2011.
She has called for a "federal solution" for Labour, with the Scottish leader taking full control of policy north of the border.
She told the Scotland on Sunday: "We're committed to the idea of a more autonomous party and we recognise we've got to deliver that to end suggestions that the Scottish Labour Party is a branch office of anything else."
But Labour's only Scottish MP Ian Murray told the BBC's Sunday Politics Scotland programme there had been no discussions with Ms Dugdale or Mr Corbyn over his voting at Westminster.
"We are all incredibly busy, I don't see why that is any sort of revelation. It seems slightly irrelevant, Parliament is not sitting at the moment," he said.
"There have been no issues in terms of voting at the moment that we have had to have that discussion on.
"It doesn't really matter whether or not I take my whip from the Parliamentary Labour whip's office or the Scottish party whip's office. It is whatever is in the best interests of the country."
Reacting to Mr Corbyn's comments, Mr Hosie told Sky's Murnaghan programme: "I think the issue is, do the Labour Party leadership in London yet understand what drives the passions for political change in Scotland, and I suspect they don't, because many of the lines that Mr Corbyn used in his interview on television this morning were the same old lines we have heard for years.
"I am just not sure that they really get Scotland yet in the way that they really ought to."
Pressed on whether Scottish voters might view Labour as the vehicle for UK-wide change, Mr Hosie said: "That was the argument before the 2015 election and we were very clear, we can't work with the Conservatives, but we could have done a deal with Ed Miliband, and indeed we potentially at some point in the future do deal with Mr Corbyn.
"But it has got to be the right deal, where we don't just have a Labour leader saying no to Trident, we actually have a Labour Party and a shadow defence secretary who say no Trident as well.
"And we don't just have a Labour leader who says no to austerity, but we actually have a Labour Party which doesn't sign up to Tory spending cuts.
"Now this is years into the future - we've got the (Scottish) elections of 2016 to come first and I think the credibility of Nicola Sturgeon's Scottish Government compared to the shambles of the Scottish Labour Party will be night and day when the people come to choose next spring."