If it can be done , Can I do the electrics and you do the gas ? Or do I have to get someone in to do Both for me to get the certificate for the gas ? Ahhh so confusing
If the cable and the copper wire is very thick chances are the electrical side is fine and everything is on a single fuse and only the cooker is supplied by this fuse.
On the gas side things get more fun. If your pipe is too small, or the pressure too low it cause issues. Generally you should have less than a 1 milli bar drop between the outside supply and the appliance when it is is fully operating. Standard gas pressure is 20 mbar at the metre so you would expect an operating pressure of 19 mbar at the appliance. Any less and there is a *theoretical* problem.
Lets say you have a gas hob with a low pressure of 12 mbar and you have a pan boiling some pasta on the stove. You also have a boiler on the same supply line. The request for heat of the boiler kicks in and fires the boiler, this could cause it to fire and result in the boiler causing the hob flame to being extinguished. At some point the boiler cycles itself down and the gas become available to the hob. Effectively you have a gas leak.
Many hobs might have micro bore piping and will have lower pressure. Some of them shouldn't really be connected according to modern British Standards.
But don't take my word for it. I'm not a plumber / gas safe person. I have however read several thousand pages of British Standard and most of the Approved Documents on regulations, flues, building regulations, electrical safety etc....