He also refused an interview although a spokesman said in a statement "the Government is not going to set an artificial deadline as to when they will conclude".
In April, Joyce and Morrison went on a charm offensive over the deal. Then, after details emerged of the gambling law concessions sought by the casino company, discussion on the issue dried up.
SkyCity had offered to cover the $350 million cost to build the centre next to its casino in central Auckland.
In return, it told investor groups, it wanted the Government to grant an early renewal of its exclusive licence to have a casino in Auckland and to allow it extra pokie machines and gaming tables. It also wanted changes to laws allowing it to "increase the efficiency and attractiveness" of its games.
The centre offered SkyCity a solution to gambling legislation which prohibited it from taking steps to grow its business by increasing the opportunities to gamble.
Documents released under the Official Information Act showed there had been 16 meetings since the announcement in June last year until May 7.
"The negotiations are expected to end at the point final agreement is reached," wrote Roger Wigglesworth, MED's tourism and events director.
Problem Gambling Foundation chief executive Graham Ramsey said he was surprised over the length of time the negotiations were taking.
"Perhaps that is recognition from the Government of the social issues involved - and not just the economic ones."
He said at least 40 per cent of revenue came from people with gambling problems.
"SkyCity's business model is based on people's problems. The more effective they are in dealing with people's problems, the more impact they are going to have on profitability."
Green Party co-leader Metiria Turei, who has been vocal in opposition, said she believed the protracted discussions were around how the deal could be "sold" to the public. She said the case which would eventually be made to the public would have to include analysis of the social cost.
She said Mr Joyce and Prime Minister John Key, who was personally involved in discussions with SkyCity before it was selected as the preferred option, had invested considerable political capital in the deal. When negotiations started, National had 53 per cent support in opinion polls. It was now at 46 per cent.
Conventions and Incentives NZ chief executive Alan Trotter has spoken of his concern over the lengthy process. "I know there are political sensitivities. It is almost inexcusable it has dragged on this far," he said.
