PM instruction outside of original contract period

Contract is Nec 3 short form. The contract period is 14 weeks. We are in delay due to the client and their teams not providing design and as such we are 3 months into a delay with no works going on. The PM wants to issue an instruction to us to deliver a piece of work that wasn’t in the original scope. Must we carry these works out as we have passed the timescales of the original contract? Or can we politely decline.

You are obliged to comply with instructions in accordance with clause 14.1.

Whilst there is no express term that states this, it would be implied that once the Completion certificate has been issued the contract is concluded and as such you would not have to carry out any further instructions after this point.

You don’t appear to be in this position and it sounds like you should be notifying compensation events in order to obtain costs and an extension of time if the underlying reason for the delay is the Employer’s fault and not yours.