OTTAWA - Elizabeth May says she won't endorse Liberal Leader Stephane Dion during the current election campaign.

There's no need. Long before the election writ was dropped last Sunday, the Green party leader had repeatedly touted Dion as her choice for Canada's next prime minister.

Yet she professed surprise when Prime Minister Stephen Harper effectively vetoed her participation in the televised leaders' debates on the grounds that she'd be little more than a stalking horse for Dion.

And she was outraged by Harper's prediction that she'll endorse Dion before the campaign is over.

"I wonder how Mr. Harper can predict what I'm going to do, which I don't intend to do, and have that count against me," May fumed.

"I know he does employ a clairvoyant who also is his stylist but unless he's relying on crystal balls, this is nonsense to say `I expect her to do something.' Ask me. I'm not going to do that."

But Harper likely based his prediction more on May's past behaviour than any clairvoyance about the future.

In April 2007, when May and Dion sealed a non-aggression pact -- agreeing not to run candidates against each party's leader -- the two issued a joint statement.

"We recognize that a government in which Stephane Dion served as prime minister could work well with a Green caucus of MPs, led by Elizabeth May, committed to action on climate change," they said.

May went further in subsequent interviews:

"Yes, Stephane Dion would like to see me in the House of Commons and I think that he should be prime minister," she said, adding with a laugh: "Of course, I'm my first choice for prime minister but he'd be very good as second choice."

May also vowed to defend Dion's record and character, calling him a man of "deep integrity and extraordinary character."

"I admire Stephane Dion enormously. ... I think it would be despicable to hide the truth from Canadians when I think Stephane Dion's a fine person."

May now says she's not endorsing Dion, just being realistic about her chances of winning the top job herself.

"I haven't endorsed Mr. Dion. I've consistently said that I am my first choice for prime minister," she said in an interview Tuesday.

"I also believe -- and this is something that's so novel in politics that people don't know what to do with it -- that I should be realistic and truthful."

So, if the election is realistically going to come down to a choice between Harper and Dion, May added: "I consistently say a minority with Stephane Dion as prime minister, with enough Greens to keep us on track for positive change ... is the honest answer."

That may not constitute an endorsement as far as May is concerned, but Harper isn't the only one who's failed to appreciate her fine distinction on that point.

Her warm praise of the Liberal leader has caused some internal grumbling within Green party ranks. It was particularly loud when longtime Green member Briony Penn announced her decision to run for the Liberals, citing May's praise for Dion as the inspiration for her defection.

"What Elizabeth May is implying is that yes, we should vote strategically for the Liberals if necessary and that Dion is green enough," former Green deputy leader Andrew Lewis said at the time.

Indeed, May explicitly made the case for strategic voting to stop Harper during the past two elections. She was part of a coalition of environmentalists and social activists who urged voters to "think twice."

During the 2007 Green leadership contest, rival contender David Chernushenko accused May of having actually asked some Green candidates to consider withdrawing from the 2006 election to avoid splitting the centre-left vote and thus helping the Tories.

May rejected Chernushenko's characterization of her actions but acknowledged that she did speak to some Green candidates one week before the 2006 vote.

"I was calling them in desperation to say, `What could we do?' Could you for instance interest the Liberals if they were interested in talking about proportional representation? Was there room for a coalition there?"