Fredericton MP Keith Ashfield was promoted to National Revenue by Prime Minister Stephen Harper on Tuesday. (Submitted)

Prime Minister Stephen Harper handed Keith Ashfield a promotion in Tuesday's cabinet shuffle, naming the Fredericton MP as Canada's new minister of National Revenue.

Ashfield will retain his watch over the Atlantic Canada Opportunities Agency, but he is also adding the National Revenue and Atlantic Canada Gateway responsibilities.

Ashfield won the Fredericton riding in 2008 after 15 years of Liberal rule. Before entering federal politics, Ashfield served as the natural resources minister in the former Bernard Lord government from 2003 to 2006.

Ashfield's promotion was made possible after New Brunswick Southwest MP Greg Thompson's decision on Saturday to retire from politics.

Harper paid tribute to Thompson, who will remain as a MP until the next election, on Tuesday outside of Rideau Hall after announcing the cabinet changes.

"Having been elected to the House of Commons six times, Greg has been remarkably conscientious and effect of any serving the people of New Brunswick and the people of Canada. For almost four years, he has been a minister in one of our most important responsibilities and one of the finest ministers in that area of ministers of veterans affairs that this country has ever known," Harper said.

New Brunswick is keeping its second seat in the Harper cabinet.

Fundy-Royal MP Rob Moore is being tapped as minister of state for small business and tourism, which was vacated when Diane Ablonczy was moved to minister of state for seniors.

Harper also singled out Moore during his post-shuffle remarks in Ottawa.

"Rob has been a valuable member of our team," Harper said.

"He will now represent New Brunswick and work for all of Canada as a minister of the government and I congratulate him."