Do you mean selling short or buying long?
If you are 'shorting' something, it generally refers to you selling something that you do not own, hoping to buy it back at a cheaper rate because you expect the price to go down. But the same can apply if you do own the 'something'. So do you expect the price of the pound to fall further? Hoping to buy back those pounds later for less foreign currency? (or buy more pounds for the same amount of foreign currency?)
If you have a 'long position', it means that you are holding something expecting the price(value) to increase.
So do you mean that you would be buying pounds now, hoping that the value will increase? Hoping to sell them later for more foreign currency? {There is no dividend involved with currency holdings.)