I wondered if anyone else has had this problem. Intermittently when I am parked on an incline, the automatic handbrake doesn't hold the car, and I have to use the handbrake manually to balance the clutch and move off. However, occasionally when doing this, the manual handbrake won't hold at all, and the car just revs as if isn't in gear, and obviously when you take your foot off the brake it just rolls forwards or backwards and there is no way of stopping it except with the footbrake.

While on holiday, we had to engage the help of some hefty chaps to hold the car, to stop it rolling into a stone wall, and no amount of cajoling would make the handbrake engage - just lots of revving.

Any ideas? Is this a mechanical or an electronic fault do you think?

Could be the handbrake module. You need to get a diagnostic check to see if any fault codes flag up. 

Thanks Steve. I did take it to the garage, but at the time the diagnostics didn't show up any faults, and the garage weren't aware of any problems like this being reported.

I have booked another visit in early November when they are going to try something called Odis... I hope this may then be sorted out.

Doesn’t all of this suggest caliper associated issues, or is this too old-hat and simplistic? 
Kind regards,

Gareth. 

Will mention this when I take the car back to the garage. Thank you, Gareth