I’m no employment law specialist, but in my opinion if an employee works for you (you have to pay them)
I always take staff on based on three months trial, after this they get a contract of employment, sub standard performance is a disciplinary offence, a verbal warning (or coaching) then a written warning, a final written warning, then the sack.
Obviously gross misconduct (stealing, assault etc) leads to instant dismissal.
Some of you on this forum are referring to your staff as though they are self employed or contractors, where then I think you would have a legal case to defer payment until the job in question was carried out to a reasonable standard.
One clause I do put into my contracts as well as cost of uniform being deducted is that if the employee doesn’t give me the statutory notice required and work it, any holiday pay owed to them is forfeited.
If you choose to employ someone you have to pay them for the hours they work, if you’re not happy with the standard of work, you go down the road of warnings which can lead to dismissal, not paying them isn’t a very good idea.
Best regards
Paul