Hello Gordon,
It could be either of your options, but I doubt it.
Possibly contaminated clutch plate - engine oil or clutch fluid, or the start of the failure of the clutch slave cylinder etc. but worth getting gearbox and engine mountings checked.
You could try:- in a safe place, and with no forward obstructions , put the car in second gear and bring the clutch pedal up slowly until you just reach the bite point. Hold revs at say a steady 1500rpm and depress and gently release the clutch pedal just in and out of the bite point. Keep doing that for a couple to three minutes and see if that results in any (temporary?) imprevement.
Kind rergards,
Gareth.