With 1.2 engines (I'm certain 1.4 engines are the same) I've seen several cases where the clutch was super-heavy and in all cases, it was the clutch itself that was worn out - not the hydraulics (sorry). Often the release bearing chews into the tips of the diaphragm spring fingers at any distance from 160,000km onwards (100,000 miles). Sometimes the fork also needs replacing due to wear, so be prepared to rush out for a replacement fork halfway through the job.
I suppose if the clutch is 'stiff' but not 'heavy', that could be a blocked hydraulic hose, but it seems unlikely - did you mean stiff or heavy? You might like to try taking the hose off and seeing if the pedal is smooth to operate. Then reconnect and bleed the air out of the clutch, but I really doubt this will make any difference (a blocked hose is unlikely).
-Alex