As with many S1 the hose from the brake master reservoir to the clutch master cylinder was in bad state on my car (sweating brake fluid and looking tired).
The genuine Lotus part is certainly not a bargain at £59.64 + VAT!
The difficulty with this hose is that the ends slightly differ in size and it needs to be brake fluid resistant.
After a bit of research I found that the Cohline 2337 hose will do the job.
But it may be bought at places in UK too, like this one here:
The hose does fit at both sides and I fixed them using permanent style ‘Ein-Ohr-Schellen’ → ‘One-ear-clip’ (don’t know the english name for those clips).
Mine was sweating a little bit.
As i work as a mechanic at a Fiat/Abarth garage i ordered one from a Fiat Doblo.
I paid a few euros,a lot less than original but as good as original!