Elise S3 SC clutch issue

[ceejay]

Left the Elise over winter garaged and went to Silverstone a couple of weeks ago and lost the clutch. No visible fluid leaks so replaced the master cylinder and bled system with a pressurised kit. Car drives fine for a few miles then clutch goes spongy then goes completely. Bled it 3 times now but keep getting the same problem. Any ideas appreciated.

[BertBert]

Slave cylinder?