Immigration Minister Jason Kenney has apologized to Alberta deputy premier Thomas Lukaszuk for referring to him as an "a**hole" in an email.

The move came after opposition MPs hammered Kenney in question period over the incident, calling on him to make amends with Lukaszuk.

The email, obtained by CTV's Ottawa Bureau Chief Robert Fife, was a response to an inquiry from a Conservative caucus member. The member wanted to know if Kenney and other MPs from Alberta were interested in meeting with the province's deputy premier.

Lukaszuk will be in Ottawa on Thursday, and was requesting a lunch or dinner with the federal caucus while he was in town.

Kenney flatly rejected the request in an email that went out to the addresses of 26 members of the Alberta caucus, along with MPs' assistants, when he hit "reply all."

"I say a definite 'no' to Lukaszyk," Kenney wrote last Wednesday. "I don't think it makes sense to create a precedent to do a special caucus meeting for every visiting minister from the provincial government.

"Plus he is a complete and utter a**hole."

In his email, Kenney spelled Lukaszuk's name incorrectly.

Both interim Liberal leader Bob Rae and opposition MPs had demanded Kenney apologize in the House of Commons on Tuesday.

"Given that his reprehensible comments are now public, will the minister of citizenship and immigration take this opportunity to apologize to Mr. Lukaszuk?" asked NDP MP Linda Duncan, who represents the riding of Edmonton Strathcona.

Rae also fired at Kenney, saying his comments were "extremely pejorative and extremely negative.

"It's a simple question," implored Rae. "Will the minister stand up and say ‘I'm sorry?'"

While Kenney has reached out to Lukaszuk, he appeared unwilling to back down earlier during question period.

Kenney did not apologize in the House, instead referring to the Conservatives' "tremendously close" relationship with Alberta and Albertans.

Under the Conservative government, Albertans have enjoyed phenomenal economic growth, tax cuts and increased immigration levels, said Kenney.

In particular, the Conservatives understand and support oilsands development, said Kenney.

By contrast, NDP Leader Thomas Mulcair referred to oilsands development as a "disease," said Kenney -- referring to the opposition leader's controversial assertion that oilsands development was afflicting the country with "Dutch disease."

Kenney also accused the NDP and the Liberals of not respecting or supporting western Canadians, referring specifically to their support of the gun registry and their resistance to the abolishment of the Wheat Board.

Both the gun registry and the Wheat Board have had low levels of support in Alberta.

But Rae fired back, saying that Kenney had still not apologized for his comments.

"I would ask the minister if he would not agree, as Preston Manning once said," ‘When you're deep in a hole, the best thing you can do is stop digging,'" said Rae.

"Why won't he stop digging and say I'm sorry?"

After Kenney apologized, Rae composed a short poem for his Twitter followers: “Poor Jason, his mouth full of feet; he pressed ‘send’ when he should have pushed ‘delete.’”

In the past Alberta's Deputy Premier Lukaszuk has been critical of federal immigration policy, and has called on Ottawa to allow more immigrants to come to Alberta, which is dealing with a shortage of skilled tradespeople.

According to some reports the email crystallizes the concerns of many members of the Alberta government who feel there is a growing divide between the federal Conservatives and provincial PCs.

Alberta Premier Alison Redford went so far as to open an office in Ottawa recently to serve as a sort of provincial embassy in the capital, to strengthen relations with the federal government.