Q:

"Populus Romanus Quiritium" as vocative?

In Latin Prose Composition by John Arbuthnot Nairn (Cambridge UP, 1926; p. 5 of "Versions" section), I find the following as a translation of Shakespeare's "Friends, Romans, countrymen, lend me your ears":

Populus Romanus Quiritium, amicique et cives mei, benigne me attenteque audiatis.

Is this correct Latin? It seems to me that Populus Romanus Quiritium needs to be vocative. But Nairn was an eminent Latinist and I have not so far found any other errors in his book, and it's a little hard to believe that he would have made such an elementary blunder. I've searched for the phrase Populus Romanus Quiritium but have not been able to find it used in direct address (while on the other hand Cicero uses popule Romane in the vocative).
Is there any possible justification for the nominatives here?

A:

It does indeed look like direct address where the author forgot to use vocative, but it is not the only option.
It is possible to read your sentence this way:

Listen to me kindly and carefully, as the Roman nation of citizens, as my friends and as my compatriots.

Viewed like this, the use of a nominative without any added words (like the English "as") is perfectly grammatical.
This gives the sentence a different tone, but it says essentially the same thing as the English "Friends, Romans, countrymen, lend me your ears".

A:

This question has now been answered by Cerberus, though his answer was posted in regard to a different (related) question. It seems that there are examples from Livy and Lucan (at least) of the form populus being used as a vocative (though popule is also attested). So Nairn is justified.

