And then there were 6.

Dr. Eric Hoskins made it official on Tuesday, announcing he'd be joining the race to be the next Premier of Ontario and leader of the provincial Liberals.

 He resigned as minister of children and youth services last week, a prerequisite set by McGuinty for making a leadership bid.

Hoskins joins Gerard Kennedy, Sandra Pupatello, Charles Sousa, Glen Murray and Kathleen Wynne in the leadership race that's to be decided in late January.

Potential Liberal leaders have until November 23rd to launch their bids and sign up new members who will vote for delegates to be sent to the Toronto convention.

Kennedy joined the race on Monday and took aim at McGuinty's move to prorogue the Ontario legislature, promising to recall members ``as soon as possible'' if he becomes leader.

Kennedy lost to McGuinty in the 1996 leadership race and lost  he federal Liberal leadership to Stephane Dion 10 years later.

Hoskins, who represents the Toronto riding of St. Paul's, is perhaps more well-known outside political circles as a celebrated humanitarian who started War Child Canada with his wife, Dr. Samatha Nutt.

They have a 7-year-old son, Rhys.

The Oxford-educated Rhodes scholar is an Officer of the Order of Canada and received the United Nations Lester B. Pearson Peace Medal as well as the Governor General's Meritorious Service Cross.

Hoskins was first elected in a 2009 byelection that was triggered when former cabinet minister Michael Bryant left politics, and was soon elevated to cabinet as minister of citizenship and immigration.

He'll join Newstalk1010's John Tory on the Live Drive at 5:35 on Tuesday afternoon.

With files from Katie Franzios