Could I use horticultural fleece to porte to protect brassicas when I plant them out?

Oh do you mean to prevent the cabbage moth? You could try it. I also realized that slugs make a beeline for brassicas and they leave a disgusting slime everywhere. For slugs try the Sluggo, Bug Geta or something like that.

If planting area is out of any strong wind it will be OK to use just thrown over loosely.the plants will still grow but may look not so nice, pigeons are my main problen

You need to create a tunnel or cage with heavy wire to create a hoop-like construction or use canes and then cover with plastic netting and pin down along the edges. That should last for ages and keep the little blighters away.

I don't know the nomenclature in the UK, but here in the States, we would look for "floating row cover" for that, not the heavier "frost cloth".

Thanks for all the answers.

Have you looked at Enviromesh? More air flow than fleece.

Thanks Steragram, I do have enviromesh, but the space I’m looking at is quite small, and my enviromesh is very big!

Cut some off?

Or fold up the edges if you want to keep it big for a later bed.

That’s what I will do, Tug. It’s just a small area with the brassicas, only about 6 of them, which my neighbour gave me.
I couldn’t bear to cut some off Steragram, it’s such a lovely big piece!