Opposition parties are questioning why International Development Minister Bev Oda didn't immediately reimburse taxpayers for expenses incurred last year when she switched from a five-star hotel to an even more luxurious establishment in London, England.

Oda was supposed to stay at the five-star Grange St. Paul's Hotel, where she was to attend a conference on international immunizations. But she had her staff rebook her into the Savoy, which cost taxpayers $1,995 ($665 per night) on top of $287 for the cancelled room at the first hotel.

On Monday, hours after The Canadian Press revealed the higher expenses, Oda repaid the hotel difference and the cancellation fee.

"The minister personally paid the portion of the expenses in question," spokesman Justin Broekema said in an email to CTVNews.ca.

A $16 orange juice ordered by the minister at the Savoy was also repaid, Broekema said.

He didn't say whether Oda paid back the expenses for a car and driver she had used that cost up to $1,000 per day. Oda had ordered a luxury car and driver in London to shuttle her the two kilometres between the conference and the Savoy.

Some have suggested that Oda went to the Savoy because the Grange did not have smoking rooms.

Speaking on CTV's Power Play, interim Liberal Leader Bob Rae said it's well known that Oda is a heavy smoker and that's why she may have refused to stay in a non-smoking hotel.

Regardless, Rae said, "it doesn't sound right, it doesn't look good."

NDP Leader Thomas Mulcair told Power Play that "nobody believes" Oda would have paid back the money unless it had made the news.

"She has a history of spending money … questionably," he said.

The symbolism isn't lost on Canadians as the federal government cuts spending, including pensions and essential services, NDP House leader Nathan Cullen said outside the House of Commons Monday.

"I want her to stop staying at five-star-plus hotels . . . I want her to start being a minister who actually believes in her file that says that the world's poor need our attention, not some high-flying aristocracy," he said.

Cullen called the situation "offensive" and said if the Conservatives want Canadians to tighten their belts to reduce the deficit, they should do the same.

In a statement, Liberal international co-operation critic MP Mark Eyking said Oda's trip "highlights her penchant for lavish extravagance."

"Ms. Oda must explain why the 5-star hotel on site was not up to her standards and why she only repaid this gross extravagance when she was discovered by the media," he said.

Documents on Oda's trip were obtained by The Canadian Press under the Access to Information Act.

Gregory Thomas of the Canadian Taxpayers Federation told Power Play he thought federal ministers would be "terrified" to incur such controversial expenses under Prime Minister Stephen Harper's rule.

"It's really over the top," he said, noting that he's also aware of Oda's smoking habit, which could have played a role in the hotel switch.

"We're waiting for the prime minister to send a message to his government that he's still paying attention," Thomas said.

Twitter lit up Monday morning as the controversy erupted.

"Well the good news is Bev you are trending on Twitter, the bad news is . . ." tweeted comedian Rick Mercer.

"When Bev Oda gets fired, it will be with a gold-embossed, bejewelled pink slip or NOTHING," tweeted another.

"The only serious thing I have to say about Oda: She's called the Prime Minister's bluff. She's realized he doesn't fire ministers, not ever," read another.

Oda's hotel change-up was similar to a controversy that raised the hackles of the opposition and taxpayers when she rejected a minivan for transportation and chose a limousine.

The agency she oversees - Canadian International Development Agency - suffered about $380 million in cuts this year as the Conservatives attempt to reel in a $31 billion deficit.

A political staffer travelling with Oda stayed at the cheaper hotel, which is no shack - it features views of St. Paul's Cathedral, an enormous glass atrium, four restaurants and five bars.

While in London, Oda represented Canada at a donors conference for the GAVI Alliance, a global health organization that works to immunize children in poor countries.

Canada has given $253 million to GAVI since 2001. Microsoft chairman and philanthropist Bill Gates attended the conference, as well as British Prime Minister David Cameron.

Oda has been criticized for champagne tastes in the past.

In 2006, she used limousines to ferry her to and from the Juno Awards ceremony in Halifax, racking up $5,475 in bills.

When the expenses were criticized in the House of Commons, she said she had reimbursed the taxpayer $2,200 of the bill.

A year later, Oda billed taxpayers more than $1,200 for another limousine ride that took her to both a government event and a party activity.

The NDP cried foul when those expenses were not spelled out in the government's public disclosures.

With files from John Size and The Canadian Press