Too late to plant early potatoes?

Thanks for the reassurance, I'm in Cambridgeshire, on heavy limestone boulder clay, vile stuff and slow to warm up, but the slowly-expanding veg patch is on what was once a muck heap and has had plenty of manure and grit dug in over the last couple of years. The raised beds near the house aren't big enough for potatoes and I've just refilled a lovely old tin bath with strawberries, if I'd found them last week I'd have put them in there. It's the first time I've tried Lady Christl - Kittie, I remember reading that you recommended them. It was a hopeless failure last year with some other variety, Duke of York I think. I did two tubtrugs of them, and just one row in the ground, got one helping of tiny potatoes and slugs got the rest.

I've popped them in rows and covered with a fleece tunnel so the hens and rabbits don't dig them up. I haven't used these tunnels before, the hens might think it's a challenge...rabbit-proofing the plot is next weekend's job, before anything green goes in!