It may well be, but I'm not necessarily sure. I think to an extent it's more a case of recognising the political circumstances of a country where, unfortunately, a ridiculous amount of people feel insanely proud of the fact we were a bunch of dicks to foreigners 100 years ago and stole a load of shit off of them. I don't have a nationalistic bone in my body, and my idealistic view of politics would be that nobody else does either, but I don't really know how the Labour party can win if they don't try and convince the myriad voters that want to stick flags up their bums that they should vote for them too.
Also, for what it's worth, I know posts like mine don't really help, because I think everyone knows that the left wing don't like nationalism and attempts to flag shag are always going to come across as a bit hollow.