Mr Keating confirmed he had had discussions with the Planning Minister Pru Goward about the new panel, but said he had achieved the design objectives he wanted to see at Barangaroo.

"I was interested in the headland park and that's gone ahead." he said.  Mr Keating said it was a mistake for the former Premier Barry O'Farrell to scrap the hotel which was to have been built on a pier in Darling Harbour, which had necessitated the granting of new site onshore for the a hotel/casino.

Documents obtained under Freedom of Information laws reveal that the government plans to appoint the Government architect, Peter Poulet as chair of the new panel, and Shelley Penn, a Victorian architect and chair of Canberra's National Capital Authority to oversee the latest modifications. A third member will also be appointed.

The panel will be responsible for making recommendations on the design for the new hotel/apartment block/casino which, if approved at 275 metres will be Sydney's tallest residential tower, outstripping the World Tower by 45 metres.

It would be nearly one third taller than the tallest office towers now under construction at Barangaroo South (209 m) and 100m taller than the approved height for the hotel over the water.

The panel will also have to assess myriad changes that will increase the gross floorspace at the site by a further 20 per cent to a total of 681,008. Floorspace has nearly doubled from the plan which won the design competition. By way of comparison, a large supermarket is approximately 4000 square metres.

Some of this increase is accounted for by the casino tower, but it also includes 18,000 sq m located in the void under the headland, and a  64,275 sq m floorspace increase in buildings at Barangaroo Central. The Barangaroo Delivery Authority says it intends to achieve the extra space without altering heights, which means the buildings will become bulkier.

The panel's role will be confined to giving advice with the ultimate responsibility for approval resting with the Department of Planning and the minister.

Ms Penn, an architect from Victoria, has already done a "snapshot review" of Barangaroo in 2011 for the incoming Liberal government. It was mildly critical of some aspects of the design so far.

The report noted: "The community is still concerned about the 'visual bulk' of the towers, which rely on good design and the planning provisions to be successful."

It recommended that the towers needed to be made to look sufficiently different, while still belonging to the same "family".

Of most concern was how the podiums of the buildings would be experienced at street level. "There is some legitimate concern that the vision for the whole of the site requires further development. Accepting there are three clear precincts, it is important to ensure the precincts work together as a whole, with effective physical and conceptual connections which help make the place legible and engaging, as well as ensuring clear linkages to adjacent areas and the Sydney."

A Lend Lease spokesperson said : "The updated master plan including the new hotel location (MOD 8) is expected to be lodged in the coming months." The Barangaroo Delivery Authority is responsible for lodging MOD9 covering Central Barangaroo and Headland Park.

A spokesman for the minister declined to comment on the design advisory panel.