What are your thoughts on the question of the PM having accepted a programme that subsequently is shown to be contra the contract requirements? Can the PM withdraw acceptance? The Contractor is, at the moment, unwilling to correct and is using the (erroneous) acceptance to claim the requirements of the contract have changed and therefore the contract is acceptable now
Bad news is that you can’t withdraw acceptance of the last programme. The good news is that they HAVE to submit a revised programme at the interval stated in contract data part 1 (normally every 4 weeks or every month) and now you can reject their next one as it would not be either practicable or reflect their plans realistically. If you have rejected their last programme then you can make your own assessment of any future compensation events - including what effect you believe this will now have on their programme.
The PM can change his mind, but not without redress. Clause 60.1(8) deals with the PM or Supervisor changing a decision they have previously communicated to the Contractor. Accepting or not accepting a programme is one of the PM’s most important decisions.