Sticking clutch 308 QV

Has anyone had any experience on what might be causing a sticking clutch on my '83 308 QV. I went out in her today and it was fine, then suddenly starting getting stiffer until by the time I was at home it would only return with the aid of a well placed toe! Had to push her back into the garage in the end.
Cheers
Rik

 

I'll give it a go, just seemed strange to go so quickly