There are some recommendations below from Poppy and the team as well embroidery club members. Do check back for updates.
Merchant and Mills: beautiful fabrics and haberdashery merchantandmills.com/
Ray Stitch: great medium heavy plain fabrics www.raystitch.co.uk/
Croftmill: great variety of medium heavy and lightweight fabric. www.croftmill.co.uk/
Empress Mills: great selection of fabrics including a great organic selection www.empressmills.co.uk/
Quorn Country Crafts: for appliqué cottons www.quorncountrycrafts.co.uk/
The Cheap Shop Tiptree: good for cotton canvas, cotton poplins, polka dots www.thecheapshoptiptree.co.uk/
Hometown Rochester: Looks like a lovely shop. Their ‘useful fabrics’ has calico and ticking www.hometownrochester.co.uk/
Alice Caroline: beautiful liberty prints and a good/dangerous remnant section www.alicecaroline.com/
Fabric Chicks: good selection of lightweight cottons, Coats Moon thread www.fabricchicks.co.uk/
Truro Fabrics: a great selection of fabrics in different weights including cotton canvas, needlecord and denim www.trurofabrics.com/
Coast and Country Crafts: an aladdin's cave of fabrics and craft supplies www.
Fabrics Galore: a wide selection of different weight fabrics. www.fabricsgalore.co.uk/
The Village Haberdashery: looks great for fabric and extra such as hoops and webbing https://thevillagehaberdashery.co.uk/
Always Knitting and Sewing: great selection of fabrics and threads www.alwaysknittingandsewing.co.uk/
Cuddle Plush Fabrics: great for waterproof and food safe fabrics https://www.cuddleplushfabrics.co.uk/