Unless you have huge loan payments/creditcard balances, how can it be hard to manage on £1700 a month, after housing costs? You might need to be frugal, but I wouldn't expect anyone to be destitute at that level.
As per the old saying, you cut your cloth according to your means. The reality is that once you have more money, unless you are ruthlessly sensible, you find ways to spend it.
For example, when my eldest was a baby, I was a single parent with a net income of £1300 or so a month. From that I paid mortgage of £500, childcare costs of £300, travel of about £120, plus all the other regular bills, and I still had enough to pay for 'extras', and put some away as savings. I then met someone, household income effectively doubled, yet we never seemed significant better off (not least because we then moved and doubled our mortgage and childcare costs!)
I'm now on my own, my earnings are much higher, but I'm also paying a mortgage of £1500 a month, so my 'disposable' income - after essential bills paid (bigger house, so all much higher) - isn't that much greater than it was however many years ago.
I do agree the current situation was caused by Labour's overspending. They obviously wanted to be socially responsible, and help low earners, but the money wasn't/isn't there. Hence the current need for spending cuts etc.