clutch shudder on take off

[ixlix]

Hi guys. My 06 zetec has started to shudder on take off in 1st. Shifting to any other gear when moving is fine. Doesnt happen all the time but when it does it almost feels like the front end is tramping even at low speed.

Is this the beginning of the end for my clutch?

Also how do I find out my flywheel size as I've read there's several different sizes for the focus.

Thanks
Alex