The PM does not have the right to do anything about this - you're talking about an amendment to the contract between yourselves and the Employer which has to comply with clause 12.3 i.e. be agreed, confirmed in writing and signed by the Employer and the Contractor. So your quibble isn't with the PM at all.
Presumably when you priced the project under the framework it was on the basis that X1 applied and you can demonstrate that your Prices do not include any element of risk for inflation? If so then you have a good case to claim mistake, especially given that X1 was stated in CD pt 1. You just need to agree with the Employer which indices are appropriate to use.
Presumably when you priced the project under the framework it was on the basis that X1 applied and you can demonstrate that your Prices do not include any element of risk for inflation? If so then you have a good case to claim mistake, especially given that X1 was stated in CD pt 1. You just need to agree with the Employer which indices are appropriate to use.
