A member of the Provincial Cabinet’s Board of Management and Priorities & Planning committees, he also sat on the Legislative Administration Committee, the Select Committee on Energy and served as Chairman of both the Law Amendments Committee and the Select Committee on Gasoline Pricing.
Like many of his Liberal colleagues, Byrne fell victim to the Progressive Conservative sweep in the 1999 election, losing his seat by only 264 votes.
In 2002, he co-chaired the successful leadership bid of Shawn Graham to succeed Thériault.
In 2003, he was elected president of the New Brunswick Liberals and he was re-elected in 2005. Byrne ran and won the riding of Fredericton-Lincoln running as a Liberal candidate in the 2006 election. Following the election, he stepped down as president of the party and was returned to the cabinet as Minister of Business New Brunswick. Minister Responsible for Population Growth, Minister Responsible for Service New Brunswick, Minister Responsible for Red Tape Reduction, and Minister Responsible for Communications New Brunswick.
He was subsequently appointed Minister of Finance, Minister Responsible for the New Brunswick Liquor Corporation, Minister Responsible for the Lotteries and Gaming Commission and Minister Responsible for the New Brunswick Investment Management Corporation.
Byrne failed to regain his seat in the general election of 2010, when the Graham government was defeated by David Alward and the Progressive Conservative Party.
He served as also Chief of Staff in the Office of the Official Opposition and Chief of Staff/Principal Secretary in the Office of the Premier. He is the President and CEO of Clonmore Associates.
