Myfabrics.co.uk is actually a German company, despite the uk web address. It matters not to me, they are extremely reliable, but I know some prefer not to buy from abroad.
There is also a Dutch company called jerseyfashion.nl which I have used a few times for their stretch sweat-shirting and children's novelty printed jersey fabrics.
I worry about the effect Brexit will have on being able to buy fabrics from these European suppliers. I suppose we will have to pay import duties and VAT post Brexit, which will increase the costs significantly.