"If there is a cost to that, which there is and it will mean higher prices and even some job losses, it is a price I am willing to pay because of the principle of paying a living wage."
Mr Thompson was sacked by the EMA in 2011 after he argued that the 12 per cent pay gap between males and females was partly because some women took sick days during menstruation.
Green MP Catherine Delahunty, whose bill proposing disclosure of pay rates by gender at workplaces sparked his comments, yesterday welcomed his new stance.
"I gather he has had some sort of epiphany and I think he should be given credit for listening and for changing his position," she said.
But Council of Trade Unions president Helen Kelly warned workers not to be taken in. "He has been instrumental in an attack on working people over the last 20 years and the result is that we now have families working fulltime and living below the poverty line, so it's a bit rich for him to say that he should be elected on the basis of the living wage," she said.
Mr Thompson wrote on his website fairpoint.co.nz that his "change of heart" stemmed from a conversation several years ago with Ralph Waters, an Australian who was then head of Fletcher Building. Mr Waters said Kiwi wages were too low because "taxpayers rather than consumers are paying the difference between a living wage and whatever lesser amount people earn".
"I actually changed my mind," Mr Thompson said.
When the unions began the $15 minimum wage campaign, he went to see Mr Key at the National Party office in Greenlane and suggested a package deal of changes that business wanted to employment laws, but with a promise to raise the minimum wage to $15 "in a faster way than would normally be the case".
"He said, 'No, I'm sorry, National will not be doing that' - which I was not surprised at," Mr Thompson said. "I know my own organisation would have opposed it."
Alasdair Thompson
• Social Credit candidate 1984, 1987.
• Mayor of Thames-Coromandel District 1989-98.
• Commissioner of Waikato Area Health Board in late 1990s.
• Chief executive of Employers and Manufacturers Association 1999-2011.
• Sacked for linking women's low pay to taking sick leave for menstrual pain.
• Standing for Auckland District Health Board.