In a report to its planning committee, Bath and North East Somerset Council admitted the contentious glass and ceramic scheme had 'polarised opinion' but nevertheless recommend the design for approval.
The authority has been swamped by both letters of support and objections in response to the practice's planning application for an additional 800m2 of much-needed gallery space for the 18th century museum (Parry's museum extension plan causes heated battle in Bath ).
In the agenda for the meeting, to be held tonight (25 July), the council said it was facing one of its most controversial decision in recent times.
The report reads: 'In conclusion, it is considered that on a close balance, this proposal can be recommended for planning permission and listed building consent.
'Having regard to the development plan the issues is finely balanced, but it is evident that it is not possible to say with certainty that the development will harm the character or appearance of the conservation area, that is ultimately a subjective assessment which must be made by the members of the committee.
It concludes: 'In short, this is a proposal which raises astonishingly complex issues in terms of the subjective interpretation of planning policies which are themselves designed to be flexible.
'The task facing members boils down to the making of an assessment of the extent to which the benefits of the proposal are judged to outweigh any perceived harm to the historic environment.'