NEC ECS: Works Information referred to in Contract Data - Conflict

We are in an NEC ECS Option A Contract with the Client which has a defined Works Information consisting of a description of the works [an overriding paragraph rather than detail…e.g. "Supply of all required labour, plant (including materials, management, supervision, and engineering) required to facilitate the complete installation of the Electrical, Lighting, Fire Detection and Alarms,…as required within this Subcontract Works Information and comprising this front sheet and the following documents (on enclosed CD unless otherwise noted)]
The following documents the Contract data refers to is a Drawing schedule. The statement made in the Contract data for the drawings schedule states “The following drawings, which describe the parts of the subcontract works”. Within this list of drawings are other documents referenced. These “other” documents contain the full unamended scope, specifications, design details, roles and responsibilities.
During the Tender Stage, we were furnished with WI documents which was amended as it clearly defined what works we were to be doing and which documents and drawings were referenced. Essentially it contained everything listed in the Drawings list under the Contract Data but was specific about the works the Contractor was to undertake, the roles the Contractor was to perform, the responsibilities of third parties and the project manager, etc as it referenced the information from the “other” documents (mentioned earlier in the query).
The Project Manager has implied that our Works Information is the description of works (not comprehensive enough as the Tender documents has not been referenced) and the drawings listed in the Contract Data.
The Project Manager has assumed that the description of works (which includes words like “all” “supply” “installation”) and all works shown within the drawings (and design documents) are to be undertaken by the Contractor, but the Contractor believes they are to only undertake the works listed within the Works Information issued at Tender stage. As an example, the Contractor is installing the lighting column, but the Employer is providing the column. The drawing just states supply and install lighting column.
The problem we have is that the WI issued at Tender stage is not referenced anywhere in the contract and therefore it is proving difficult to demonstrate what we priced and signed up to. If the WI documents were issued under a CD but not explicitly listed in the contract data, then does this mean it has no relevance? Or does it mean that it’s implied as part of the subcontract, just not referenced?
We have stated to the Project Manager that our scope is the WI priced at Tender and that the description of works stated in Contract Data gives a general overview of the works. The detail is in the WI documents which are not listed in the contract.
As a side note, the Project Manager has referred to the WI documents issued at Tender stage in contractual correspondence (generally when rejecting NCE’s!) so he does acknowledge that it exists.
Unfortunately, the description of the works is general at best as it doesn’t define the specifics whilst the drawings and documents listed contain everything (even works we would not tender for), regardless of whether we are doing the work or not.

This sounds like a dog’s dinner of a contract and underlines the importance of a clear contract (in its entirety) so that both Parties know what they are signing up to … in fact one question is : have the Parties actually signed a contract ?

I fear that there are multiple questions in here which, without having the contract documents (what are they ?) and a timeline of when they were issued, work started etc. I cannot answer.

Yes, it is indeed a dog’s dinner! The contract is signed and I don’t think a full on contractual disagreement will materilise but i’m just preparing my company in the event the project goes to dispute.

Thanks for your reply.