The federal government says it won't be helping Queensland with a $600 million cost blowout to replicate a stretch of the M1 on the Gold Coast.
State Transport Minister Mark Bailey has revealed the first stage of the so-called second M1 - a six-lane, 45km arterial route from Nerang to Logan - will now be $2.1 billion.
That's up $632 million on the $1.5 billion it was originally expected to cost.
Mr Bailey says the project has always been funded 50/50 by the state and federal governments and he's written to Acting Prime Minister and Infrastructure Minister Barnaby Joyce seeking an extra $316 million.
He blamed the blowout on delays by the previous Liberal National Party government and an overheated market that was charging more as governments pour money into infrastructure to keep the economy ticking during the pandemic.
"That delay has meant that we have been caught in the middle of an unprecedented boom in investment in infrastructure projects across Australia," he said.
But federal Urban Infrastructure Minister Paul Fletcher said Queensland shouldn't get its hopes up.
"The Queensland government is responsible for the procurement, management and delivery of this project," the minister's office said in a statement.
"The Commonwealth's commitment is set at $750 million, we do not provide open ended insurance against mismanagement of a project by the state government."