Ontario NDP leader Andrea Horwath says it worries her when her candidates express different policy opinions than those in the party's platform.

Horwath was a guest on CBC Radio's Ontario Today on Thursday and was asked about candidates who have expressed policy opinions that break with the party's platform.

One candidate, Joel Harden, is running in Ottawa Centre, where analysts see the NDP having a chance at taking a seat from the Liberals.

At an all-candidates debate last week, Harden told the crowd while the official NDP policy on funding Catholic school boards is to essentially support the status quo, his personal belief is the public and Catholic school boards should be merged.

Harden says he’d merge the two into a public board, even though the NDP platform is for the status quo. (I wonder if the party brass knows Harden is going rogue.) —@jchianello

"It is worrisome when I hear these things as a leader," Horwath said.

"When people are vetted … they're asked to sign on to the values and specifics of our platform. They're committing to stay in tune with what we're bringing forward."

NDP Leader Andrea Horwath says candidates are asked to commit to party values as part of the vetting process. 0:32

Increased scrutiny

Horwath was also asked about increased attacks on NDP candidates which analysts have said match the party's rise in the polls.

Particularly, host Rita Celli asked about the Progressive Conservative focus on what they're calling "radical" candidates who have been portrayed as Sept. 11 conspiracy theorists and another who is against wearing Remembrance Day poppies.

"[On] the issue of the poppies and other personal opinions people have, [those] are opinions people carry all over the world," Horwath said.

"What I'm confident in is that every member of our team is completely in favour of and supportive of our platform and is prepared to work very hard to deliver the change Ontario needs."

She added there are many people who say and do things they regret later.

Horwath also talked about hydro, provincial debt and a potential minority government scenario during the hour-long show.

Liberal leader Kathleen Wynne was on the show last week, Green Party leader Mike Schreiner is scheduled to be a guest on Tuesday and the Progressive Conservatives have told CBC they won't make leader Doug Ford available.