8.8 million population, which probably means a bit less than 7 million potential voters because kids and others can't vote and it's a relatively young city. Only 5 million registered to vote at present.
So still 2 million is worryingly low, but not as bad as if there were 8m potential voters.
Blair's government removed their permission to work while waiting for decision. That seems to have created an immoral incentive for decisions to be made very slowly at some later point, because if the government doesn't decide, the ignorant can't complain as much about refugees taking jobs.