|This employee chose a poor spot to park their van.|
You have the worst employee ever. They are completely useless at their job, and have no interest in trying to improve. They then apply for a job at another company and the other company asks for a reference.
Under UK law you can't give someone a bad reference, but if the law allowed you to be honest, would you complete the reference honestly and admit that this employee was useless at their job? Or would you give them a fictitiously impressive reference pretending they were really good, in the hope that they get the job and that way you get rid of them and they become someone else's problem?