The Manitoba Liberals went after Premier Gary Doer as the legislature got back in session Monday, saying he is in a conflict of interest.

Doer announced last month that he was stepping down and the following day, he was introduced in Ottawa by Prime Minister Stephen Harper as Canada's next ambassador to the United States.

Doer has not given a date for his departure, but the NDP leadership convention is set for Oct. 16-17.

As ambassador-designate, Doer is in a "clear conflict of interest" by staying on as premier, said Liberal Leader Jon Gerrard. Doer's new job means his boss is now Harper, not the people of Manitoba, Gerrard said.

"It impacts, for example, the ability of the premier to stand forcefully up against the federal government when the interests of the hog industry are not being well supported or when the interests of people who've been flooded in the Interlake are not supported well, or when Tembec workers are locked out," he said.

"He has a very clear conflict of interest standing up for both Manitoba very forcefully and also being responsible to the prime minister of Canada."

But Doer said the Liberal leader doesn't know what he's talking about and Progressive Conservative Leader Hugh McFadyen said the Liberals are just trying to score cheap political points.

"It's not a problem. There's a law and I will follow it, always. I'm the designate, not the ambassador," said Doer.

McFadyen used his first moment in the new session to crack a joke, asking Doer tongue-in-cheek, "How was your summer? Anything new?"

On the serious side, McFadyen said he wants to focus on the issues of the day, such as crime and H1N1 preparedness, not whether Doer should step aside.

But the fact Doer didn't appoint an interim leader does show one thing, said McFadyen — it signals a lack of confidence in his ministers.

"The only message he's sending right now is loud and clear: 'I have no confidence for them to run the show in my absence.' I think that's worrisome," McFadyen said.