This comes up and is attributed to Gordon and Slater solicitors. Might be worth lookin on their site.

No, a physical "leaving period" cannot be enforced, as an employer cannot physically stop you from leaving.

However, your contractually agreed-upon notice period is legally binding, and if you leave early without your employer's written consent, you could be in breach of contract. This can lead to consequences like losing pay and benefits, or in rare cases, legal action from the employer, especially if they incur significant costs finding a replacement,