Deposit not paid, but acknowledged

Hi

Any help with this is appreciated.

Tenant moved in on 1 Nov. Signed a lease agreeing to pay one month's deposit and monthly rent. Now we're in Jan and he's paid nothing (no rent, no deposit) whilst waiting for the council to process benefit claims.

He's two months in arrears so I want to serve a s8 notice on him. My concern is that he's not paid a deposit (and so it's not been protected under TDS) but the lease says "The Landlord acknowledges receipt of the Deposit from the Tenant".

I believe that the deposit is less relevant in s8 cases, but I'm nervous that there is a tenancy agreement acknowledging receipt of a deposit which wasn't paid and wasn't protected.

Should I file the protection with TDS in case this comes up when I try to enforce the s8 notice, or should I not do anything with TDS and be ready to explain the situation if it goes to court?

I'm also thinking I should serve a s21 notice to expire at the end of the 6 month period in case the s8 gets rejected. Will i need to protect the (non-existent) deposit before this is valid, or does the fact that he's not actually paid the deposit mean I shouldn't?

Thanks