Found this today,
Miracle-Gro Patch Magic Grass Seed, Feed and Coir 10 Patches 750 g Shaker Jug - £5.46 inc free del
i was going to buy it from B&Q, but this is cheaper.
From the amazon website
The revolutionary Miracle-Gro Patch Magic offers a convenient, easy to use, one step solution to bare or thin patches in your grass.
Made up of a superior quality (free from agricultural grasses) mix of grass seed, coir growing substrate and Miracle-Gro fertiliser, grass is guaranteed to grow anywhere, even on concrete, and grows 50% thicker with 50% less watering.
The unique, super-absorbent growing material acts like topsoil and changes colour to indicate when more watering is required.
1 x 750g of Miracle-Gro Patch Magic to reseed up to 10 patches (based on a 45cm diameter)
Triple action coir, seed and feed for one step lawn patching
Guaranteed to grow anywhere - even grows on concrete
Super absorbent growing material acts like top soil, only better
50% thicker grass with half the water
Superior quality seed free from agricultural grasses
Contains a mixture of dwarf perennial rye grass and fine fescues