Re: Well done students...
...of if it's an 'assured shorthold tenancy', as I believe most are these days, assuming they have been there for the tenancy period on their contract (6 or 12 months usually), give them 1 month's notice of termination of their rolling contract without need for a reason.
One of the bad things about the UK is how little protection tenants have compared to other European countries, especially when it comes to things like rent increases, or the landlord deciding to sell up to someone who no longer wants to let the property.