Appleby and Pinsent Masons have now been appointed as legal advisers for the deal, following the request for proposals (RFP) issued in the summer.
Also reported by PPP Bulletin in July, the government appointed PwC as financial consultants for the deal.
The outline business case has now been approved by the government and the next stage in the procurement process, prior to the release of the RFQ, will see another RFP issued for advisers for the official environmental impact assessment and marine engineering work.
Financial close is expected to be reached in early 2015, according to a government official.