Is it possible for the Contractor to amend the Subcontractors Sectional Completion Onus?

We have a Subcontractor whereby it is our contractual obligation to hand over an prescribed area of the site, to Others. The Contractor wishes to give us a CE and amend the remit of the Sectional Completion, whereby another area of the site is now required to be handed over, in place of the previous area. This is all under the banner of the original Sectional Completion onus, i.e. if we don’t achieve it then we would be liable for damages.
Is this allowed? I am aware dates may be change but the scope of works pertaining to Sectional Completion?

NEC3, Option A by the way

Jonathan I am in no way an expert on this but my view of this would be that clause X5.1 states section in italics which means that they are listed in the contract data. There is no instruction that the C can make to change the content of the contract data meaning in my view they cannot simply add new areas as and when it suits. However, clause 12.3 does allow a change to be made but only with the agreement of all the Parties. I do not see how you as the Subcontractor would accept this without some form of changes to Completion and/or the Prices, or dare I say a change to the amount of Delay Damages for the new section.

In terms of changing the scope of works pertaining to the sectional completion, X5.1 also states that wherever in the terms of the contract it makes reference to

The subcontract works
Completion and
Subcontract Completion Date

Then they are concerned with the section as well as the whole of the subcontract works.

Clause 11.2 (2) defines Completion as when the Subcontractor has done all the work which the Works Information states he is to do by the Completion Date. Clause 14.3 allows the C to change the WI with no limitations as to which part, so in theory they could change the scope of what Completion looks like and this would be a CE under 60.1 (1).

It may be worth trying to understand why the Contractor is wanting this change, they could be under pressure from the PM in the head contract. It also sounds like they are open to having the Completion and/or Prices changed as they are suggesting to raise a CE for this.

Like I said above i am in no way an expert on this so it will be interesting to see what the panels view is on this.