OTTAWA -- Prime Minister Stephen Harper swiftly shuffled his front benches Wednesday following the resignation of embattled International Co-operation Minister Bev Oda.

The hole created by Oda's resignation on Tuesday had been expected to be filled later this summer in what could have been a wide-ranging shake-up, but ended up being only a minor change.

A spokesman for the prime minister said Wednesday's small change is the only one necessary and no further shuffles are planned.

"That's it. There is not going to be anymore. Everybody has got their portfolios, they have a lot of work in those portfolios," Andrew MacDougall said.

"A lot is ongoing and the prime minister in particular wanted continuity."

The lack of a major cabinet shuffle prompted critics to accuse the Harper government of being blind to problems in their midst.

Oda had been one of those problems.

She was embroiled in a series of scandals through her years in government, culminating recently in revelations of spending excesses at a conference in London.

She resigned under intense pressure from caucus and from the public.

She was replaced Wednesday by Julian Fantino, the government's front man on the fumbled F-35 file.

His responsibilities as associate minister of defence were handed off to New Brunswick MP and Minister of State for the Atlantic Canada Opportunities Agency Bernard Valcourt.

"These changes to the ministry ensure continuity as we focus on creating jobs, growth and long-term prosperity," Harper said in a statement.

"Mr. Fantino and Mr. Valcourt bring strong leadership experience to these important positions."

No notice was given of the swearing-in ceremony, which was held earlier Wednesday at Rideau Hall.

Fantino had previously been tasked with the complicated business of military procurement, including the controversy surrounding the purchase of new fighter jets.

He stick handled the F-35 file for the government until it was finally shunted into the hands of a government advisory committee.

Fantino, who now receives a promotion to a full ministerial post, said he was looking forward to the job.

"Our government has made great efforts to improve the effectiveness and accountability of Canada's aid programs. I will continue to make that a priority," he said in a statement.

"I will work tirelessly to advance the Canadian values of freedom, democracy, human rights and the rule of law."

The issue of military procurement is far from dormant as the Canadian forces seek to revitalize themselves in the face of billions in budget cuts.

Valcourt is a longtime Conservative who once served in former prime minister Brian Mulroney's cabinet.

"I am humbled to take on this responsibility as associate minister of National Defence, and look forward to serving all Canadians in this new role," Valcourt said in a statement.

"I look forward to working with ministers (Peter) MacKay and (Rona) Ambrose, as we ensure value for money at DND for military procurement."

MacKay was one of the ministers rumoured to be up for a change this summer as he's been also dogged by the controversy over fighter-jet spending.

Speculation had also been that Harper may promote some of his rookie MPs to more senior positions in a bid to freshen the public face of his caucus.

NDP MP Charlie Angus said he wasn't surprised Harper didn't clean house.

"This is a prime minister who gets really stubborn. So it took Bev Oda having to quit to really making a move," he said.

"It's not good enough ... He needs to set the reset button, but he's either too obstinate or too blind to do it. So he's shuffled cards with the mediocre. He has not attempted to bring any new blood in. And I think it's going to stick to him."

Liberal MP Carolyn Bennett said the lack of a broader shuffle speaks to Harper's belief that he's always right.

"It's pretty difficult for a prime minister to be giving a failing grade to ministers who were merely following orders," she said.

"He obviously isn't prepared to admit there have been some pretty weak performances and pretty weak ministers, in spite of the fact he makes all the decisions."

The opening left by Oda isn't the only one Harper needs to fill.

There currently four vacancies in the Senate: one in New Brunswick, one in Nova Scotia and two in Ontario. Three more are expected by September in Ontario, Quebec and Newfoundland and Labrador.

And a patchwork of positions are open in the highest ranks of the bureaucracy and military.

A new chief of the defence staff is expected to be named by summer's end, which could set in motion a domino effect for military leadership.

Meanwhile, both Industry and Environment are now without deputy ministers as the highly respected men in both positions have announced they're retiring.

There are also at least a dozen vacancies at the assistant deputy minister level.

Now that Harper has signalled he's through changing his cabinet, the shuffling of deputy and assistant deputy ministers is likely to begin.

The bureaucratic changes are made by the clerk of the Privy Council, in concert with the prime minister.

"Ideally, they would try to co-ordinate. If the prime minister's intention is to have a shuffle, he would take into account the clerk's views," said Ronald Bilodeau, who served as deputy Clerk of the Privy Council under Jean Chretien.

"They don't want to change the minister and deputy minister in the same week. You need to have some continuity."

The moves in the civil service can send as much of a signal at the policy level as a cabinet shuffle sends politically.

"If they're moving laterally, it's hard to say why," said Bilodeau.

"But if they're moving up, it indicates that they trust this person and want them to deal with problems."

On the electoral front, Oda's decision to step down will also require Harper to call a byelection for later this year.

He also needs to call one in Calgary Centre, formerly held by Tory MP Lee Richardson, who left in May.

Both ridings are likely to remain in Tory hands.

But a third byelection could be required in the Toronto riding of Etobicoke-Centre, pending the outcome of a court case. Results there are less than certain.

That case goes to the Supreme Court next week.