Kiama MP Gareth Ward has criticised Shellharbour MP Anna Watson over her "sudden interest" in progress on the Albion Park bypass.
He said Ms Watson's calls for the release of a yet-to-be completed study into bypass options followed years of inactivity.
"In what can only be a considered as a blatant act of political opportunism, members of the NSW Labor Party have, after 16 years in office, raised their concerns about this issue," Mr Ward said. "Congestion on the Princes Highway through Albion Park did not emerge with the change of government - it is an issue that the Labor government conveniently ignored."
Mr Ward said his lobbying resulted in the $100,000 study now under way - and that the bypass would remain on his agenda.
"Once this initial design work is completed, I will seek further funds from the government to prepare the planning, route selection and design," he said. "I believe the Albion Park bypass should be a high priority.
"Obviously it hasn't got as high a priority as Berry because, in the case of Berry we've actually seen a loss of life."
He called for a 50-50 funding arrangement between state and federal governments for the Princes Highway, similar to what exists for the Pacific Highway.
Ms Watson claimed she was responsible for the study.
"The only reason the NSW government found $100,000 to conduct this so-called study, which no-one can see, was after public pressure from me just days after the 2012-13 budget," she said. Ms Watson also responded to Mr Ward's claim that the federal government should help with funding for the Princes Highway.
"For 16 years every single Liberal-National Party roads and transport spokesperson told the Illawarra media the Princes Highway was a state road and therefore a NSW government responsibility," she said.