Labour leader David Shearer says the Prime Minister's job forecasts for a proposed SkyCity convention centre are based on "back of the envelope" calculations.
John Key previously said a deal with SkyCity to build a new convention centre in Auckland in return for up to 500 more pokie machines would create almost 2000 jobs.
Shearer today described the estimate as "optimistic", in response to a feasibility study done for the Government by hospitality and travel consultants Horwath Ltd in 2009, which showed the centre could provide as little as 319 long-term jobs.
"This is a far cry from the 900 construction jobs and 800 staff positions John Key has touted and includes taxi drivers and hotel workers. The Prime Minister needs to go back and check his figures," Shearer said.
The National party has been criticised by the public and other political parties that the proposed deal would increase problem gambling.
Shearer said using job creation as justification for selling off legislation that rewards SkyCity is "irresponsible".
"This was a shonky deal from the start, and one which Kiwis overwhelmingly oppose. If this is National's magic bullet for the economy, we are in trouble."
Shearer said "back room" deals should not be the way business is done in New Zealand and called for an economic plan with credibility.