Although you are under an NEC3 ECC Option A, you also say that the demolition and re-routing works is agreed on an 'open book basis', which I am assuming is the 'pre-let' works you describe. If agreed on an 'open book basis' I am also assuming the 'pre-let' works is either a separate contract, or an instruction by the PM which varies the scope of works, which is a compensation event under the main contract and valued as Defined Cost under the Shorter Schedule of Cost Components. My answer assumes the latter (main contract).
You say the Employer is not very familiar with NEC, although it is the Project Manager who you should be interfacing with under the contract, so be mindful of any agreements or arrangements that the Employer wants to make as these should be formally confirmed under the correct contract procedure by the PM.
Although you are obliged to Provide the Works in accordance with the Works Information it seems that the disagreement is not whether the 're-routing of service lines at a road crossing' is included in the scope, but whether it is part of the main contract or the 'pre-let' works.
If the scope is clearly included somewhere (main contract or 'pre-let works') then there is no question that you are obliged to do the work. It seems that the matter comes down to payment, that is as part of the pre-let works (CE procedure) or deemed to be included in the activity schedule. Consequently, notifying a CE would not be appropriate and what you actually need is clarification.
The referral to the Senior Management (Representatives) might be useful, but is an optional referral 'by agreement' and does not replace the right to refer a dispute to an adjudicator at any time.
You say the Employer is not very familiar with NEC, although it is the Project Manager who you should be interfacing with under the contract, so be mindful of any agreements or arrangements that the Employer wants to make as these should be formally confirmed under the correct contract procedure by the PM.
Although you are obliged to Provide the Works in accordance with the Works Information it seems that the disagreement is not whether the 're-routing of service lines at a road crossing' is included in the scope, but whether it is part of the main contract or the 'pre-let' works.
If the scope is clearly included somewhere (main contract or 'pre-let works') then there is no question that you are obliged to do the work. It seems that the matter comes down to payment, that is as part of the pre-let works (CE procedure) or deemed to be included in the activity schedule. Consequently, notifying a CE would not be appropriate and what you actually need is clarification.
The referral to the Senior Management (Representatives) might be useful, but is an optional referral 'by agreement' and does not replace the right to refer a dispute to an adjudicator at any time.