I really recommend Pure sunflower spread. It tastes more like butter than Vitalite too. Also the sunflowers are UK-grown and processed, so the carbon footprint will be lower. If you can't get it in your local supermarket, most Holland & Barrett shops will store it in their fridge-freezer section at the back (along with many other vegan products). However, despite this, they also use a bit of palm oil and - similarly - I can't find information about whether it's sustainably sourced. Biona used
to make palm oil-free spreads, but no longer. Again, I don't know about the credentials.
But if you have a subscription to the Ethical Consumer magazine, you can easily find out:
I have noticed that Suma's
Olive spread is palm-oil free, and that all their products that do
use palm oil are heavily accredited. I can only assume that the companies above are doing likewise, particularly Pure because I think it is the same company as America's Earth Balance
and I'm pretty sure they've made sustainability efforts.