HALIFAX -- The race to become the next leader of the Conservative Party of Canada is underway and a familiar name has thrown his hat in the ring.

"I'm in. Stay tuned," MacKay wrote on Twitter this week -- implying with those four words that he's coming out of political retirement.

MacKay hasn't spoken publicly about his desire to replace Andrew Scheer yet, but others have plenty to say on the possibility.

"I think it's wonderful news," said Cameron MacKeen. "A lot of us have been hoping Peter would do this for quite a long time and now he's officially in."

MacKeen is the former vice-president of the Conservative Party of Canada and a longtime friend of MacKay.

He says, if MacKay is chosen as leader, it will switch a lot of seats from red to blue.

"I would suggest that there's 10 people in Nova Scotia that really don't want Peter MacKay to win, and those are the 10 current liberal MPs."

MacKay was an MP from 1997 to 2015 and held several prominent positions -- including attorney general and minister of national defence -- while Stephen Harper was prime minister.

Policy expert Lori Turnbull says one of the advantages MacKay has is that he's not a sitting MP.

"For this part of the country, it means that there's a leadership race going on, a potential future prime minister of the country, and somebody with a very high profile, a very good chance at winning is from Atlantic Canada," said Turnbull, a Professor at Dalhousie University School of Public Administration.

MacKay did not seek re-election in 2015 and did not run to replace Harper.

He recently made headlines after commenting on Scheer's loss to Justin Trudeau in the last federal election.

"To use a good Canadian analogy, it was like having a breakaway on an open net and missing the net," MacKay told an audience in the United States.

Turnbull thinks there is a lot of interest in his candidacy.

The leader of the Nova Scotia Progressive Conservative Party says MacKay running is not only good for the provincial party, but it is good for all Nova Scotians.

In a statement, Tim Houston said, in part: "I have always emphasized that I am a progressive Conservative. I believe in a government that is fiscally responsible and socially progressive; that promotes individual achievement and personal responsibility; listens to its people; and is an environmental leader. I know Peter stands for those same principles."

The thought of MacKay running for leader of the Conservatives has many people talking. Some even say he could sway their vote.  

"I'm just curious to see what somebody new would do," said Carolyn Cochrane."You know. I don't vote for the party, I vote for the person."

The Conservatives will elect a new leader in June and the rules have changed since the last leadership race.

Candidates will each need to submit a non-refundable registration fee of $200,000 and collect 3,000 signatures from registered party members.

Feb. 27 is the deadline for applications.