Clutch (pedal) safety switch

[Ukcass]

New to the forum with a first question. I have a Citroen C4 Picasso 2 2014 which is temperamental at starting. I have figured out a swift press of the clutch and press of the start button together normally solves the trick.
If I simply hold the clutch pedal to the floor and attempt to start it switches off my start screen on the dashboard and further presses of the start just cycle this screen on & off.
Google searches of the issue have lead me to the clutch pedal switch, which I bought, but now I find my model doesn’t have this on the pedal. Can anyone send me a picture of where it is located please or assist in the non starting fault if I’m barking up the wrong tree.
Other faults my Google search associated with the clutch pedal switch was no cruise control but mine is working fine, despite this fault.

[RichardW]

There's a position sensor which is an integral part of the master cylinder. Failure of the master is quite common, so it probably needs replacing. If you can get it on a diagnostic computer you should be able to see the clutch position and confirm it's not going to full extent.

[Ukcass]

Would I not have more symptoms if my master cylinder was failing. If anybody can show me the position of the switch,I can meter it out myself. Is the switch adjustable? as I have no other symptoms.
Could it be clutch linkage worn and not supplying sufficient movement to register it as pressed?