I am getting very at some of the misconceptions on this thread, particularly skiwear's comment about civil servants. As a civil servant our department first started childcare vouchers November 2007. Most outside employers offered them long before that. While they are a help they only cover £243 a month and affect your pension and future maternity pay rights.
When I had DC4 I left work (thankfully) to be a SAHM. Within a few weeks of leaving our car broke down. DH's pay barely covered the mortgage and bills so we were already struggling- this was just impossible. No repair meant DH couldn't get to work so back I went
He worked nights and I worked afternoons and weekends (2 jobs, then 3). I came in as he went out and we sort of passed on the stairs. We did that for years. We were lucky that FIL retired when DC4 was 2 years old because it meant he could step into the breach when we couldn't quite overlap. DC4 spent more time with grandad than me
I swapped my 2 jobs for one fulltime when they were 12, 10, 8 and 6. The summer holidays were a nightmare for many years- no tax credits or flexible working when they were small, and we couldn't afford paid childcare. DH took 2 weeks leave, I took a different 2 weeks leave, grandma had them for another week and the other week was ad hoc.
ATM I'm working 3 days a week but will have to go back to FT in July. DD's nursery is £30 a day so for working an extra 2 days a week I will be better off by about £160 a month. Doesn't seem worth it really.
On paper we are earning a fair bit now between us but we've never got enough to pay the bills and we don't have a flash lifestyle. If diesel goes up much more DH will be paying to go to work, so it will be time to think again