As far as jobs, the way you describe "entitled people walking around with a Croydon facelift and fag in hand while living on benefits" its hardly going to be them taking the jobs away is it?
So if they don't have jobs - who's paying for them to be able to live then?
Having more children means you are putting a lot more burden on the welfare state - and with that I also mean the NHS, schools, etc. And yet, you do NOT pay more income tax. And don't say your kids will pay tax one day. They cost the state money the minute they are born, and yet the state derives no income from them until they start to work (and there's no guarantee that they will). If they put a tax on people who want more than two children (e.g. £500p.a. for third, £750p.a for fourth, £1025p.a. for fifth, etc.), I don't think that many people would actually choose to have large families. A welfare state is actually pretty difficult to sustain with a large population.
I mean... seriously, is it just cantspel who sees the problem here?? There is a reason why a lot of sci-fi movies/books are based in a world with a one-child-policy... because it is conceivable that such a thing could happen (China anyone?).
As cantspel said - if you want to go back to the large families of Victorian England AND have a reasonable standard of living, then we better start dying earlier, and go back to high infant mortality rates. With modern medicine, that won't happen... so what do you think will happen instead?
How do you imagine the world will be like in 40-50 years time, if EVERYONE started having 4+ kids when we're already struggling today??
Is NO ONE concerned about the world your DC will grow up in? Or is everyone just happy living in blissful ignorance - like our parents did before us? Because at some point, the world has to wake up to its problems. I start to believe that by that time, it will be a little too late. Future generations will probably detest our generation that lived in a golden era of reasonable standards of living and were too blind to see the problem at hand.