On Wednesday Guy's and St Thomas' Charity and Lambeth Council made their closing submissions to the Founder's Place planning inquiry.
Mr Medlin outlined the CSTA's objections on the grounds of daylight, sunlight and density issues which mean that "this proposal would not provide residents with an acceptable standard of privacy."
He also set out the CSTA's position on the conservation issues before the inquiry. The association believes that the Holy Trinity Centre makes a "positive contribution" to the Lambeth Palace Conservation Area and could – along with 10 Royal Street – "be maintained and incorporated into a design."
Mr Medlin told the inquiry that "CSTA do not feel that there are adequate proposals to ensure the safeguarding of Archbishop's Park."
He made a point of distancing the CSTA from the support given to the scheme by the Friends of Archbishop's Park group: "The CSTA, and others in the local community, regard themselves also as friends of Archbishop's Park; they live next to it and naturally want to see its long-term success as a resource for the community."
He highlighted to the inspector the evidence given by Kenneth Sabel, the council's expert witness on heritage matters, that concluded that "both the Holy Trinity Centre and 10 Royal Street do make a positive contribution to the character or appearance of the conservation area and form part of its architectural or historic interest."
Mr Hockman also highlighted the proposed development's impact on the setting of Archbishop's Park, which was one of the reasons given by councillors for refusing planning permission last year.
"The appellants' proposals will plainly have a severe impact upon the setting of Archbishop's Park," he said, before going on to discuss "the way in which the Holy Trinity Centre, together with the trees, form part of the essential character of the park at its northern end."
Referring to a new sectional drawing supplied to the inquiry by the appellants, Mr Hockman drew the inspector's attention to measurements which showed that at their closest the pruned canopy of the row of London plane trees at the northern end of the park would be just 2.5 metres from the edge of the proposed buildings.
He addressed issues of design, including the sense of enclosure created by the development on Royal Street, questions of overlooking and privacy, daylight and sunlight.
"What is ... most definitely not accepted is that the benefits can only be secured by granting approval for the present proposals," said Mr Hockman.
He also praised the evidence given by Michael Ball on behalf of the Waterloo Community Development Group – which is backing the proposed development – for its "clarity and balance".
"It is entirely possible to pay regard and respect to his approach whist disagreeing with his ultimate conclusion," he said.
He attacked the "historicist approach to conservation" taken by Lambeth Council which he said had been rejected by the secretary of state after the Heron Tower, Shard and Potters Fields planning inquiries.
Mr Harris rejected criticism of the charity's handling of relations with its protected tenants, voiced at the inquiry by Kate Hoey MP and members of the tenants' association, insisting that consultation had "gone well beyond" the levels required.
He added that the "life experience" of those currently living in Canterbury House and Stangate "will be enhanced beyond recognition" by the proposed development.
On the question of the demolition of the (unlisted) Holy Trinity Centre, he said: "The benefits of the proposal to the community so clearly and decisively outweigh the impact of demolition as to speak for themselves".
Hr Harris also described allegations of harmful overlooking as "wholly unsustainable" and the council's case on daylight issues as "fundamentally flawed".
"Turning this proposal away now is unjustified," he concluded. "It will set back the regeneration of this site unacceptably and unnecessarily. That would not represent good planning."
Although the inspector has heard closing submissions the inquiry has been adjourned until Monday 14 May to allow the parties time to complete a section 106 ('planning gain') agreement for the development.
Planning inspector Philip Wilson will then write his report and make a recommendation to the secretary of state for Communities and Local Government (currently Ruth Kelly). A final decision is expected in the summer.