Not everybody is going to be made to work full-time under the Universal Credit conditionality - despite what most people are saying here!! The conditions are based on income (rather than hours worked as used currently for Tax Credits). They are expressed as a number of hours at the minimum wage. So, for example, if your partner earns more than double the minimum wage for 35 hours a week then you will not be subject to conditionality. People with caring responsibilities will also have reduced conditionality.
A single parent will have no obligation to work while they have a child under 5 or are caring for someone with disabilities. With a primary age child they will be expected to look for work compatible with school hours (note, "look for" not necessarily find - if you can't get the work you will still get UC as long as you can prove you are looking - just like JSA now). Parents of secondary school age children will be expected to look for work paying 35 hours at min. wage.
In a couple, one will be considered to have caring responsibilities and will have the same conditionality as a single parent. The other is expected to earn 35 hours at min. wage.
I can understand the thinking behind this regime. Currently I know people who work 16/24 hours a week to maximise benefits and "it's not worth the bother of working more" - this will be an even bigger problem under UC. Looks like a nightmare to administrate though, particularly for the self-employed. What about someone working 32 hours x min. wage receiving training - would they be made to swap to a dead-end job with no prospects? And who exactly is going to check this conditionality - the job centre is busy enough with the unemployed without millions more joining in?