1. Dear Adrian, a landlord has no right in law to keep a rental deposit in a situation where the tenant vacated a rented property after the landlord gave notice. So long as rent was paid for the relevant period, the landlord cannot keep a rental deposit. Be aware that your landlord has an obligation to hold your deposit on a Government backed Tenancy Deposit Scheme if your lease was an assured short term lease. Under this scheme the landlord can be fined for not having put the monies given as deposit into the scheme. here is a link which explains the scheme https://www.gov.uk/tenancy-deposit-protection/overview. My view is that your rental deposit should have fallen within the scheme.
2. Be aware that you can apply to your local County Court should your landlord have not used the scheme when he should have. Be aware that the landlord must give back your deposit within 10 days of the end of the tenancy.
3. Under the application to the County Court, the landlord can be compelled to pay a penal three times the deposit if he has not returned it and has not used the scheme.
4. Please Accept or Rate the answer as unless you do so, your Expert will not receive payment for answering your question.