Prime Minister Stephen Harper is planning a wide-ranging cabinet shuffle that is expected to see Finance Minister Jim Flaherty switch places with Industry Minister Jim Prentice, senior insiders tell CTV News.

The shuffle is expected to take place in late June or early July, and follows the sudden resignation of Maxime Bernier as the foreign affairs minister.

Sources say Flaherty wants to expand Industry Canada. That would allow Prentice, the unofficial deputy prime minister, to take over Flaherty's portfolio.

Secretary of State Helena Guergis is expected to be dropped because she's blamed for mishandling the Brenda Martin case. Martin spent two years in a Mexican prison and critics accused the government of doing little to bring her home, although she was eventually found guilty in an Internet fraud scheme.

Treasury Board President Vic Toews is expected to leave his post because of personal reasons, although he's in line for a federal judgeship.

Harper will likely announce that David Emerson will stay on as foreign affairs minister - the former Liberal MP took over the position after Bernier stepped down, and he already runs a special committee on Afghanistan.

That would open Emerson's other position as minister of trade. Sources say there are two possible candidates for the portfolio: either Health Minister Tony Clement, who is considered a solid performer in his current file, or Immigration Minister Diane Finley, who successfully oversaw the recent immigration bill.

Three backbench MPs will likely be promoted to cabinet: British Columbia MP James Moore, Nova Scotia MP Gerald Keddy, and Manitoba MP Rod Bruinooge.

Bernier was forced to resign after he left classified government documents in the home of his former girlfriend Julie Couillard, who has had personal connections with people involved in the biker underworld.

Prime Minister Stephen Harper, currently on a three-day tour of Europe, told reporters that Bernier made a crucial mistake.

"You obviously don't disclose classified materials and you certainly take adequate care to ensure that they are not disclosed and they are not left behind somewhere," he said.

With a report by CTV's Ottawa Bureau Chief Robert Fife