OTTAWA - Liberal Leader Stephane Dion will have to find two new candidates for a potential fall election after two men who won nominations just last year stepped down.

In Prince Edward Island, one of the Liberals' star candidates, Robert Morrissey, stepped aside Tuesday. Then the party announced Thursday that Saskatchewan candidate Garry Oledzki had resigned in Palliser riding.

Bloggers for both the Liberals and Conservatives have been sparring over whether the resignations are connected to the Liberals' contentious Green Shift plan.

But a Dion spokesman said the resignations had nothing to do with the proposal to shift taxes from individuals and businesses to big polluters.

And Oledzki was adamant that he was stepping down for personal reasons, about which he would not elaborate, saying he had to spend more time with his family.

"It's a very, very, very difficult decision," Oledzki said in a telephone interview with The Canadian Press. "It has nothing to do with the Liberal Party Green Shift plan.

"I believe in it, I think it's the right thing."

Palliser, which encompasses Regina and Moose Jaw, Sask., is currently held by Conservative MP Dave Batters, who first won the riding in June 2004.

Morrissey was unavailable to comment on why he decided to leave the political ring, but suggested in a news release that continuing questions over whether an election would be held any time soon was a factor.

"A number of new opportunities have arisen in the private sector which make my continued candidacy untenable," said Morrissey, who had won the Liberal party nomination in P.E.I.'s Egmont riding.

"Especially given the continued uncertainty over an election date".

Oledzki and Morrissey both said they planned to be active in the coming election, should it be held this fall, and that they would assist the new candidates in their respective ridings.

A former provincial cabinet minister, Morrissey won the nomination in November after sitting Liberal MP Joe McGuire announced he would not run again.

Egmont is considered one of the safest Liberal seats in the country. The Grits have held it in every election since 1980, with McGuire as the MP for all but eight of those years.

Prime Minister Stephen Harper has dared the Liberals to force an election this fall, promising to bring in a number of confidence measures when Parliament resumes.

Dion is expected to meet with his top strategists in Ottawa next week to devise a strategy for responding to the challenge.