Wedding Venue Cancellation Fee Advice needed please

sayitasitis

Hello all, I am hoping someone can help me with my situation. I had booked my wedding date for April 24th 2020. I had paid upfront £5000 for the venue which was then fully paid,  but part of the £5000 payment was a part payment for food (£1800)  I had not agreed final numbers for guests, however I had to cancel the wedding in Feb 2020, as myself and partner split up. The venue then stated I had to pay a further £3000 to cancel the wedding, as a cancelation fee. 
I was disputing the £3000 cancellation fee with the venue, which is not a hotel, but a purpose built venue for events such as weddings and parties. My reasoning was, that they had had £5000 from me which I accepted I had lost, but the rest of the monies were for food. Obviously we then went on lockdown, and my wedding would have been cancelled anyway, however, the venue are now still chasing me for the cancellation fee? Is this correct? Even though the wedding could not have taken place, can they still charge me this cancellation fee?