NEC ECC: Option B tender return 10 months ago – Employer only just signed the contract - what is the best way to negotiate recoverable costs from tender submission to account for market rate changes?

Political issues delayed award to the Contractor but mutual agreement between Employer and Contractor to hold off on signing the contract. During the Pre-Start meeting, the Contractor has raised the point that they wish to recover any losses for any material price increases. What is the best way to utilise the Contract to arrive at an adjustment to the tender prices to account for any increase to material prices?

I suggest that you consider if a CE has occurred under 60.1(2) in that access was not allowed, presuming there was a date(s) in the Contract Data.