The race to replace Ontario Premier Dalton McGuinty appears to be heating up with two more Liberals expected to formally announce their leadership bids this week.

Sources have told CTV Windsor that former cabinet minister Sandra Pupatello will go public with her candidacy at a Thursday news conference.

Speculation about a possible Pupatello bid spread on Tuesday evening when Ontario Finance Minister Dwight Duncan suggested that she would soon rival PC leader Tim Hudak.

“It will be fun watching Hudak concede to Sandra and Harper concede to Justin at the next general elections,” Duncan said in the message posted to Twitter.

Duncan has said that he would support Pupatello should she decide to toss her hat into the provincial leadership race. Both have represented the Windsor area.

“I think Sandra will be a terrific leader. I think she would re-energize the Ontario Liberal party,” said Duncan on Wednesday.

The premier took time on Wednesday to praise Pupatello during a conference in Niagara-on-the-Lake.

“Sandra is both a lot of fun and a lot of force,” said McGuinty. “She’s a force to be reckoned with.”

Pupatello was originally elected in the riding of Windsor-Sandwich in 1995 and eventually obtained a cabinet position in 2003. She worked on several high profile portfolios including education, community and social services and economic development and trade, before retiring from politics in 2011.

Mississauga MPP Charles Sousa also has plans to make an announcement “about the future of Ontario” on Saturday, strengthening rumours that he will enter the competition as well.

Gerard Kennedy, who lost to McGuinty in 1996 by just 140 votes, is also rumoured to be considering a leadership bid. Kennedy has held seat at the provincial and federal level.

Former cabinet ministers Kathleen Wynne and Glen Murray officially entered the race last week, both resigning from their positions to do so.

The Ontario Liberal Party will elect a new leader the weekend of Jan. 25 at Maple Leaf Gardens in Toronto.

With a report from CTV Toronto's Paul Bliss