P. Setigerum? Poppy of Troy

the stems look hairy. Poppy of Troy usually has smooth stems as it is often thought to be a variant of the opium poppy.

what are the leaves like?

this is unusual with the double layer of petals.

The leaves are small and the stems and buds are hairy.

Maybe one of the 'Motherof Pearl' strain of Papaver rhoeas?

Tugbrethil, they do look similar, but I don’t think it’s that. These were meant to be the traditional red ones, packet of seeds I had free with Gardener’s World magazine.

You can contact GW magazine on this email address: q&a@gardenersworld.com
They might be able to help.