I've just watched "Rip-off Britain" on BBC1 and two tenants had/have the most horrendous mould in their property. But it was NOT their fault and it wasn't because of lack of hygiene or lazy housekeeping skills. They used mould remover spray, they aired out their property, they knew to dry up any moisture issues. But the mould kept coming back. An assessment was made on one property and the mould was due to structural damage issues. NOT being lazy and not out of not caring about mould.
Mould spores are very nasty and can result in breathing issues, as well as other health problems. If this is you, get your council/landlord to treat the mould themselves. If the mould does come back, the council must do a structural assessment and treat the problem at its root cause.
You don't have to put up with health endangering mould: and don't let your landlord blame you and accuse you of poor housekeeping standards.