The thing about Labour getting properly tough on immigration is that...well, who's really going to buy it? They're too late if it's their intention to appeal to such a demographic. Kind of like in Scotland...all the talks now of federalism, and working properly for Scotland's interests etc have fallen on deaf ears, because the party has fallen into political irrelevance. No one really cares now - anyone who feels Scotland has been disenfranchised or not represented properly has stopped voting Labour.
I suspect anyone who genuinely, properly has massive qualms about immigration to the point where they won't vote Labour because of it has probably already stopped voting for the party. Of course, I still think it's right for the party to pay attention to the issue and engage with voters on it, but if they intend to take a hardline stance then it's not going to reap them many rewards. If they do they'd have to abandon support of freedom of movement and thus any support for a softer Brexit, and would thus cede voters to the Lib Dems on mass. Probably a lot more than they'd gain back from UKIP in constituencies they already hold.
I imagine any move towards this would be to stop the rise of UKIP in the north...but I also don't think the situation up there is anywhere near as dire as a lot of people seem to think. It's being treated similarly to the SNP situation but the SNP has already been a reasonably sized political force for decades in Scotland and always did alright...even in plenty of constituencies Labour dominated. Then they took Holyrood by force in 2011 and translated that to Westminster last year.
That's not really happened with UKIP yet...who in spite of their growth up north still don't have any core bases/areas, and according to recent polling are still a fair way off suddenly taking the north by storm. It could suddenly flourish and happen in an instant, but I'm not even sure a hollow change in tone from a party who have long been championed as liberal, pro-EU and multi-cultural, with a leader who's said he's fairly keen on open borders, is going to do much.