OTTAWA -- Former prime minister Stephen Harper raised eyebrows Monday when he publicly offered his congratulations to Viktor Orban after the controversial political leader was re-elected as prime minister of Hungary.

In a tweet late Monday, Harper congratulated Orban -- whose election platform openly demonized migrants and asylum seekers in Europe as a security threat -- for winning "a decisive fourth term" for his Fidesz party, which now holds a two-thirds majority in Hungary's national legislature.

"Congratulations to Prime Minister Viktor Orban and Hungary's Fidesz for winning a decisive fourth term! The IDU and I are looking forward to working with you," Harper tweeted.

The post prompted a number of Twitter users to point out Orban's right-wing, populist political ideology and controversial political policies.

Frank Graves, president of Ekos Research Associates, said he was so surprised by the former Conservative prime minister's tweet, he thought Harper's account had been hacked.

"Mr. Harper is a pretty shrewd character and I thought it, frankly, showed a lack of judgment on his part," Graves said Tuesday in an interview.

"There's a lot of deep skepticism about Mr. Orban and particularly his policies such that I would have thought this would be an area where you would want to give a pass."

Harper was unanimously elected chairman of the International Democratic Union (IDU) in February. The centre-right organization is made up of more than 80 conservative political parties worldwide, including Orban's Fidesz party.

The former prime minister did not respond directly to requests for comment, but Rachel Curran, a senior associate at Harper's consulting company, Harper & Associates, said the tweet was simply a standard communication about the activity of a member party.

"He's not pronouncing on the merits of Mr. Orban's government or his political campaign, he's simply congratulating him as a successful member of the IDU who recently received a massive democratic mandate from Hungarians," Curran said.

"That was the sole purpose behind his message."

Some people have been using the tweet to "get a shot at Mr. Harper," she added.

International observers of the Hungarian election from the Organization for Security and Co-operation in Europe issued a statement saying "intimidating and xenophobic rhetoric" from state-run media and "opaque campaign financing" limited the opportunity for genuine political debate during the campaign.

Curran stressed that it would be inappropriate for Harper to comment or interfere in the domestic politics of any member parties of the IDU. But she added Harper is interested in looking at ways to make the organization more active and effective.

"That's just who Mr. Harper is. He'll try and put his own stamp on the organization and get it doing something useful and productive."

Regardless of his roles and responsibilities with the IDU, Harper's tweet could be interpreted as a him being happy about Orban's electoral success, Graves said.

"It's very controversial whether this is a good or bad thing and what kind of forces are at play here," he said of Oban's electoral victory.

"I just think this is not a good area to be saying, 'I'm really happy Mr. Orban won this,' because there certainly going to be a lot of people in the advanced, western societies who would not share that view."