The only thing I can think of, if you can't use a pick, is a cold chisel and lump hammer, Derek.

Might sound daft, but what about paying a contractor to come in with a jack hammer. Noisy and I have no idea how much it would cost.

Thank you. I may have to get a contractor in anyway as the garden is on a slight slope and I wanted to try and level it but I don't think I'm going to be able to get through the ground to move any amount of meaningful soil.

I agree with BA. just think how quick that would be.

Nothing is going to grow in that horrible stuff.
Probably cheaper to get someone with some pallet wood to make raised bed cultivation for you. Building firms throw out damaged pallets, glad to get rid of them.
You can choose your own compost then, some beds for Ericaceous plants.

Sounds like you will have to resort to mechanical means to extract the flint. You may find someone who is willing to buy it from you if it is in big blocks. Have a word with building suppliers, they might come and dig it out for you...

Flint forms naturally in layers, often in chalk... If this is the case you are going to need a good load of garden soil from somewhere to aid with any future planting.

The raised-bed idea sounds more attractive by the minute.. :)

I wonder if leveling the ground is such a good idea. If it is as hard as it seems it probably won't let rain water soak away and so the existing slope will provide a means for it to run off.

My ignorance may be showing. Is this real flint--microcrystalline quartz--or is it a particularly hard clay soil found in the UK?

we do have geniune flint as used by the neolithic peoples for their tools etc. and it is really sharp :o(

Thank you to everyone for their replies. The local area soil is full of flint chippings - it's not solid flint but it feels like it when trying to dig some of the plants out of a long neglected garden.
The garden's small, but it could be useable space. I've measured out that the slope drops 106cm over the 650cm length with a width of 890cm and planned what I'd like it to look like as I think I can work with that gradient. I'd just prefer to do it myself rather than get someone in - it'll be better than joining a gym for 1 thing!

Probably use a pick or a breaker bar before shoveling, then, Choufleurie, to pry the chips apart.