I have actually found a UK supplier of fresh yeast. I may give them a try at some point, but for today, there is a soft dippy 50/50 white/wholemeal sourdough loaf warming up after proofing in the fridge and I have a 100% dark rye, roasted sunflower seed and honey sourdough loaf about to be made today. I am at the pre-ferment stage where I make the loaf to proof in the fridge overnight. The sunflower seeds have been roasted and are now soaking. I'm just busy making our evening meal (cooking chickpeas with crushed garlic and whole chili) and making our vegan bean pate (cooking the butterbeans) at the moment, so the 2nd loaf will have to wait a touch longer.
It is also not very warm here today, so my sourdough bread will take longer to rise!
Right - link to the fresh yeast in the UK.
http://www.shipton-mill.com/flour-direct/organic-fresh-yeast.htm