Clutch gone ?

The clutch seems to of gone on my TD4, well the pedal goes to the floor and stays there.I have been searching this forum and things point to the hydraulic system.On inspection the master cylinder seems loose though there doesn't seem to be any fluid leaks anywhere and the reservoir seems about two thirds full though I think the fluid does need changing as it looks milky.
Has anyone experienced this?
Is it as I hope a new master cyl or does it sound like the slave.Any pointers to help me diagnose this though I think a new master is a no brainer first as opposed to gear box out job.
Thanks

Can you get it to work by rapid pumping?

Is the clutch pedal actually still connected to the master cylinder?

a milk look on the hydraulic oil is bad get it change asap.

After futher investigation today the whole system works for a few presses and the clutch bites. Then the peddle goes to the floor and the clutch is fully engaged.You then lift the peddle back up with your hand and it seems ok again?

Master cyl seals, if fluid is contaminated seals will have gone soft