[jacquesm]

Fortunately, the Labour Party doesn't control businesses and every company is free to negotiate whatever contracts it feels like within the law, so a subset, such as 4 days instead of whatever the legal maximum is is perfectly possible.

[tomp]

Is this entirely true? A lot of state benefits are linked to hours worked, e.g. if you don't work full time, you might not get full state pension, employement insurance, etc... (Although admittedly these benefits are quite minmal in the UK, at least for London.)

[robocat]

Also some professions require so many FTE years experience to progress with professional qualifications (or maintain?).

I know a nurse that needs to do a minimum of 35 hours a week so that they can get full-time experience so that they can meet requirements for the next job.

[C1sc0cat]

There is a minimum to qualify - unfortunately a lot of employers game the system with Zero hours contracts.