PPS 6 Planning Archaeology and the Built Heritage·Page 20·3.19
Archaeological Mitigation and In Situ Preservation
Developer offers to excavate archaeological remains do not justify planning permission if physical preservation on site is both desirable and feasible, regardless of mitigation measures proposed.
It should be noted that an offer to facilitate excavation by developers will not justify a grant of planning permission for development which would damage or destroy archaeological remains whose physical preservation in situ is both desirable (because of their level of importance) and feasible.
Source — /Users/richardhill/Documents/planning-arch-project/data/documents/regional/PPS 6 - Planning Archaeology and the Built Heritage.pdf