The SNP has dismissed claims that it would be hard for it to keep a future UK government in power if it did not include the largest party in England.
There is speculation the SNP may try to do a deal with Labour in the event of a hung Parliament in May, even if the Tories win the most seats in England.
Deputy Leader Stewart Hosie said this could be justified if it meant stopping David Cameron getting back into power.
And he said voters would have no right to "whinge" in such a scenario.
Recent opinion polls have suggested that the SNP, which currently has six MPs, could substantially increase its representation at Westminster in next year's general election.
Former Scottish first minister and SNP leader Alex Salmond - who is standing himself for the UK Parliament - has talked of the possibility of the party holding the balance of power after the election.
His successor Nicola Sturgeon has ruled out any accommodation with the Conservatives in the event of no party winning an outright victory in May, prompting speculation about a potential arrangement with Labour to form a coalition or support a minority government led by Ed Miliband.
Election expert Professor John Curtice told the BBC that such an arrangement would intensify debate over the question of English devolution, since in order to "prop up" a Labour government, the SNP might be forced to vote on laws affecting only England, something the party has previously said it would never do.
Speaking on Radio 4's World at One, Mr Hosie was asked whether it would be wrong for a party that wanted Scotland to leave the United Kingdom to have a decisive say in the running of the UK government.
"I think the bottom line is if we are in the position where, through whatever mechanism, we can stop a Tory 'austerity government' and we may be able to offer help to a minority Labour administration... we would obviously want to ensure the policies that government followed were the right ones for everyone across the whole of the UK," he said.
"Let me put that another way. We have one Tory MP in Scotland yet our economy is run by George Osborne. I don't think it is right for people to whinge on a UK-wide basis if we help form part of a government."
"Unionists cannot have it both ways. They cannot argue that this is a union, a family of nations, and all the other stuff they say and then start whingeing and whining when people from Scotland form part of a majority government. That would not do at all."
Mr Hosie said the current Conservative-Lib Dem coalition had "not been squeamish" in pursuing policies, such as spending cuts and welfare changes, which he suggested were deeply unpopular in Scotland..
He dismissed suggestions that it was in the interest of the SNP to introduce policies in Scotland which "stirred up resentment" in England in order to try and drain support for the Union.
"This is politics," he added. "Obviously we have our policies and we want to see these put into practice, put into play because we think they are the best thing, not just for the people of Scotland but the whole of the UK.
"I keep hearing this argument that we do good things in Scotland on purpose to stir up resentment (in England). I happen to think free education is a good thing full stop and I would love to see it in England.
"We don't do good things in Scotland to stir up resentment... but because they are popular and necessary...I only wish there was a political party that represented the English people who took the same view."