In a speech in London about "progressive patriotism" and how the English must assert their own national identity, the Labour leader denigrated what he called "narrow nationalism" and insisted Britons could have plural identities.
He explained how the SNP's outlook meant that "identification with one of our nations was diminished by the identity with the country as a whole. Do you want to be Scottish or British? I say you can be both".
Mr Miliband claimed the First Minister had something of a problem when it came to the issue of identity, saying he knew he was "on extremely thin ice". He explained: "In the very act of leaving the United Kingdom, clearly people would not be British any more in the same sense as they were."
He went on: "Whenever Alex Salmond comes across something people quite like about the Union, he says you can have that as well – the Queen, the Army, the BBC, Britishness, the currency ... the Bank of England. It's a kind of argument that suggests he does not have much confidence in his own argument.
"People can be Scottish and British within the UK, if they feel primarily Scottish, that's fine too. But Alex Salmond can't have it both ways because if you want to leave the United Kingdom, people won't be British any more, it stands to reason ... The SNP are going to force people to choose."
The Labour leader argued that Scotland and England were "intertwined" economically, culturally and socially and that an independent Scotland could never really deliver social justice for its people.
He said: "Alex Salmond says the relationship will be like the Scandinavian countries, but once you start off with this kind of history that we have of being so intertwined, the idea you can make Scotland a fairer place but not do the same in England without causing huge issues right across the borders, it seems to me to be nonsense...
"If you want, for example, to change the way companies work. Well, you're not going to affect most employees in Scotland if you just deal with companies headquartered in Scotland because you're going to leave out of the count all of those companies headquartered in the rest of the UK.
"So it's a very simple point: if you want social justice in Scotland, you can't do it on its own, it has to be done as part of the United Kingdom."
In his speech, the Labour leader admitted his party had been too reluctant in the past to talk about England, partly because people were nervous of it being identified with "the kind of nationalism that left people ill at ease".
He said: "We have rightly applauded the expression of Scottish identity within the United Kingdom, but for too long people have believed to express English identity is to undermine the United Kingdom. This does not make sense. You can be proudly Scottish and British and you can be proudly English and British, as I am."
In response, Humza Yousaf, the SNP MSP, accused Mr Miliband of being out of touch with Scotland. He described independence as the "broad, inclusive and positive option for Scotland, in which the wide range of identities we have in our modern nation – Scottish, English, British, Pakistani, Chinese, Polish, Irish and many, many more – can all be reflected and celebrated".
Mr Yousaf added: "What Mr Miliband desires for England can only be delivered by Scottish independence, giving both nations a new relationship based around a partnership of equals, bound by a social union of our shared history and culture."