Foreign Affairs managed to spend just shy of $792 million on aid to low-income countries in 2013-14, but had $917 million available, leaving more than $125 million in lapsed funding.
The figures are contained in the recently released performance report for Foreign Affairs, the first since the department absorbed the now-defunct Canadian International Development Agency.
Those figures emerge in a week in which the Conservative government has trumpeted spending announcements of about $28 million to help end early child forced marriage and to combat violence against children in developing countries.
Liberal foreign affairs critic Marc Garneau said the lapsed aid funding, combined with unspent money in other departments, is part of a government plan to fatten the overall surplus in time for next year's federal election.
Earlier this week, The Canadian Press reported that Veterans Affairs Canada has returned $1.13-billion in unspent funds to the treasury since 2006.
"Government ministers are not signing off on authorized spending programs so they can return this money to general revenue and have bigger surplus for re-election purposes," said Garneau.
Regardless of the motivation, the figures show the government is clearly saving money on the backs of the world's poorest people, said Roland Paris, founding director of the University of Ottawa's Centre for International Policy Studies.
"This is program spending that's been authorized by Parliament and that is intended to reduce poverty and improve the lives of the people in low-income countries," said Paris.
"The government has been saving money is a stealthy way by not spending the money that it's authorized to spend."
The government announced in 2010 it would freeze foreign aid for five years to balance the budget and announced further spending cuts two years later.
When it folded CIDA into the Foreign Affairs Department, many observers warned that could lead to a reduced emphasis on poverty reduction.
Amid the cuts, the Conservative government has launched some high-profile aid initiatives. These include Prime Minister Stephen Harper's maternal and newborn child health initiative and Foreign Affairs Minister John Baird's campaign to end forced child marriage.
Baird announced $10 million towards that initiative at a high-profile ceremony this week that featured Dutch Princess Mabel van Oranje.
On Thursday, Development Minister Christian Paradis announced $17.3 million worth of programs targeting child violence and promoting access to education during a 90-minute panel discussion at a downtown Ottawa public school.
Garneau said the Liberals fully support these development priorities, but he criticized how those high-profile announcements contrast with the lapsed spending that was buried in a mandatory government spending report.
"They (the Conservatives) hope the rhetoric via the communiques and the announcements is the only details Canadians will actually retain," he said.
NDP development critic Helene Laverdiere said the lapsed funding amounted to a "backdoor" spending cut.
"The Conservatives are trying to balance the books on the backs of some of the most vulnerable people who need our support."
Laverdiere noted that Canada's overall development spending is far short of the United Nations target of 0.7 per cent of GDP. Canada's current level is less than 0.3 per cent of GDP.
Maxime Robert, a Paradis spokesman, said the government has also responded to individual crises, allocating $175 million more than planned to address troubles in Philippines, Syria, South Sudan and the Central African Republic.
"The world is facing an unprecedented number of extreme humanitarian crises," he said.
"We continue to be at the forefront of international responses to international crises."