Mr Palmer also said the company had never approached the Government seeking a $1 billion capital injection, as suggested by Mr Key shortly after it was revealed late last month the company was struggling under $389 million in debt.
"Were we talking to the Government about the possibility of capital and receiving that from the Crown? The answer is no," Mr Palmer said.
"A specific $1 billion capital injection, I'm reasonably sure we did not ask for it in exactly those terms."
Labour's SOE spokesman Clayton Cosgrove pounced on Mr Palmer's comments as evidence Mr Key had misled the public over what led to the company's near-collapse to obscure the fact that his Government's oversight of it was poor.
"I don't know how many times the Prime Minister gets to make things up without someone using the 'L' word.
"John Key cited the increase in gearing as one of Solid Energy's downfalls while at the same time his Government was requiring an increase in gearing across the board and a greater dividend."
Mr Palmer confirmed the Government was well informed, said Mr Cosgrove, and did not ask the company to change its strategy.
Yesterday afternoon SOE Minister Tony Ryall was saying Solid Energy's problems were not due to its debt.
"The problems with Solid Energy come from the fact that the board made a number of investments that didn't generate the returns that they were expecting and together with the most significant collapse in world coal prices," he said.
But Labour leader David Shearer said Mr Ryall's comments were "the complete opposite" to Mr Key's comment that a key contributor to Solid Energy's woes was that it "added gearing to a company that historically had not had gearing".
Mr Ryall said the opposition was being "deliberately mischievous".
"The Prime Minister did receive advice about the financial implications of Solid Energy proposals for a significant expansion into a national resource company," he said.
"Had the ministers been supportive of the proposal it would have required the Crown to contribute in excess of a billion dollars. In the event, ministers were not supportive and a formal proposal didn't eventuate."