NEC3 ECSC: If a Contractor is aware of ambiguity between drawings within the Work Information during Tender stage but does not raise an EW until during the construction phase is he entitled to a CE?

During a EW risk reduction meeting a Contractor stated he was aware of ambiguities between drawings at tender stage but to be more competitive he choose not to price these items, but has now during the construction phase has raised an EW to have these items paid for, would he be entitled to a CE to cover these items.

NOTE: Under the tender Works Information the following was added " Any Ambiguities between different elements of the Works Information must be raised as a clarification during the tender stage"

Secondly under 10.1 The "contractor shall act as stated in the contract and in a spirit of mutual trust and co-operation.