Actually, at least in the UK, you can't be fired without cause.
Normally you'll have to be told that you're underperforming, be put on a "performance improvement plan", and have to be given time to improve yourself, or demonstrate that you are performing well.
You can be made redundant for no reason, but you have to be warned the moment management are considering redundancies that your job is at risk, and you are able to make a case for how redundancies could be avoided, or how your position could be changed to fit into the new structure. If you are made redundant, you have to be paid extra (although it's a tiny amount and only after 2 years)