You can effectively divide the obligations of the contractor into 3 groups : those of a Supplier as listed in the Framework Contract (assuming it is an NEC contract); those as a Contractor under the ECC; and those as a Consultant under the PSC.
The answer as to which applies - as opposed to which takes precedence, which is not quite the right question - is to find out under what contract the work was being done.
The answer as to which applies - as opposed to which takes precedence, which is not quite the right question - is to find out under what contract the work was being done.