I have looked for a horn related fuse and the only one I can find is in the under bonnet fuse box and that's ok. Is there another one in the fuse board above the drivers footwell?From your earlier posts you have a lucas alarm system rather than the Pekton relay/alarm unit so you can rule out relays The issue could just be fuse related so that should be your first thing to check. If the fuses are ok, it could either be the buttons on the wheel itself or the rotary coupler (also called a squib). Check this guide for how to remove the wheel/airbag to get to the squib Little guide - Removing steering wheel and airbag
Thank you dert I will be back on it tomorrow so will let you know how I got on.
No there is no SRS light, I had hoped to get the wheel off today but I woke up with a pain all down my left side so couldn't do much at all today, Hopefully I will get back to it tomorrow.The rotary coupling is the obvious candidate as the cause if both horn buttons do not work + if the SRS light stays on (you say nothing about this). It is possible the horn button connector has disconnected in the steering wheel (unlikely but possible).