Picture posting is enabled for all :)
Surely the seed itself carries all the nutrient needed for germination? Wouldn't the compost only affect the later growth? Isn't it more likely to be the watering or the temperature, or the seeds themselves. Even though they are new seed, if they have been stored badly they could be dead.
nothing has germinated
all the seeds are in date and the packets have been bought new this year
and I have sown them as I have always done
I have used gro sure potting compost instead of my usual stuff so could it be the compost?.