Cleaning white electric hob

[PreHeatedOven]

I have what I guess must be enamel white electric hob.
It has lots of very old burnt food marks on it, what on earth do I use to get them off?

Thanks in advance

A chisel?

Before you spend lots on Ovenmate, you could try my cheap and easy method:

I sprinkle normal washing powder on and spray lightly with water (use fine mister bottle that I use for houseplants) to dampen. Leave for a bit (overnight is good but try after 30 mins if you are impatient!) It should come off with a wipe or maybe a bit of a scrub with scourer sponge.

If this doesn't work - it always has for me - then maybe try the Ovenmate? I have never used it as the washing powder always works for me.
HTH

Thanks all, I'll definitely be trying the washing powder trick first!
I have liquid at the moment darn it.

It's not chisel type marks annoyingly!

I had one of these and just coated it in Cif cream, rubbed a bit, left for ages, elbow grease, repeat rinse and voila