1996 Renault Laguna RXE automatic. Intermittent non-starting fault?

I have a 1996 Renault Laguna RXE automatic. An intermittent non-starting fault has developed in the last 4 months. It is unpredictable but when it occurs I turn the key, all dashboard lights are bright, engine doesn't even turn let alone fire up. It sometimes but not always occurs after a run of anything over 10 miles. Then I wait 30-60 min, try again, no problem.

Any ideas welcome.

Clifford Wharton

29 April 2006