Some are calling it a mid-mandate re-boot.

Prime Minister Stephen Harper is set to give his inner circle a sweeping overhaul – and he's widely expected to install fresh, younger faces to replace outgoing veterans at the cabinet table.

For a government facing slumping support in public opinion polls, beating back a series of scandals and bracing for a general election in just two years, many experts and insiders see this summer's shuffle as the most critical in Harper’s tenure so far.

Cabinet building is traditionally a delicate balancing act to ensure gender, geography and language are represented. Various factions within the melded Conservative Party – including progressives, social conservatives and libertarians – must also be factored in.

Matching portfolios with 'performers'

With five cabinet ministers already announcing their departure, Harper needs to match his key portfolios with the best "performers" in the ranks, according to David McLaughlin, a chief of staff to former prime minister Brian Mulroney.

"Now is not the time to be rewarding friends — now is the time to be completing the job," he said. "One of the knocks on this government has been a lack of clarity sometimes and lack of direction, and I think this is a real opportunity with a shuffle to clarify that."

With no signed trade deal with the European Union and unresolved pipeline issues – both touted as economic priorities for the Conservative government – McLaughlin says this shuffle needs to be a major makeover rather than a minor tweak. Harper must also signal the party is poised for regeneration and rejuvenation heading into the 2015 campaign.

"There's a staleness about some of the ministry and some of the cabinet and how they're communicating with Canadians; the look and feel of it. So there's a chance to really show some new faces and say: 'There's still life in this government yet. We're looking ahead, look at this new blood.'"

With a restless and increasingly vocal backbench, Harper must also figure out a way to keep his caucus content and united in the wake of inevitable disappointment with being left out.

"It's a leadership test that everyone in that position has to go through, and I would argue that it's going to be a little tougher now because the situation and the fact that the caucus is demanding a bit more attention and demanding a bit more independence," he said. "How he manages that will be very interesting to see."

Shuffle infuses fresh blood

Michael Behiels, a political historian at the University of Ottawa, said the timing is right for a cabinet shuffle as it will give new ministers time to settle in before bracing for the next electoral battle. It could also help switch the channel on some of the lingering scandals and put a new face on the government with an infusion of fresh blood.

"They've been in a lot of trouble in the last little while, and I think people are tired. It's been a tough slog for a lot of them – minority governments, then they worked hard to get a majority, then they worked hard to get things done," he said. "Some things worked and other things didn't, and I think some people are pretty exhausted and they now get good pensions after a period of time and some are deciding now is a good time to step down."

Geoff Norquay, principal of Earnscliffe Strategy Group and a long-time Conservative adviser, said regional vacancies set the stage for a complex, calculated, province-by-province allocation based on population and where Conservatives have seats. Achieving a male-female balance, ensuring language capabilities are met and finding the best fit for ministers with portfolios are key considerations for making the mix.

Renewal key before 2015 campaign

The mandate mid-point is a prime time to take stock of who’s staying, who’s going, and who wants more or less responsibility, Norquay said. Renewal – and the exchange of old ministers for new ones – is critical as Harper looks ahead to the next campaign.

"He's also as much as signalled there will be a new agenda this fall, so this cabinet shuffle can’t really be seen in isolation," he said. "Equally important, I think, is the announcement of new directions for the government – new policies, new priorities which we'll very likely see in the form of a throne speech."

Nancy Peckford, executive director of Equal Voice, sees the upcoming shuffle as an opportunity for Harper to boost the female count in cabinet.

Hopes for more women in cabinet

While there is a perception the Conservatives have a bleak record on females in cabinet, the numbers prove otherwise. But despite once reaching a historic high for any federal government, Peckford hopes to see more high-performing parliamentary secretaries promoted.

"They don't lack talent," she said. "Their caucus is only 17 per cent women, but many of the women who got elected in the last election are very promising …and they have already shown they have the capability and ambition to be there. So we would expect they would be given a shot at it."