The NDP candidate in Durham riding has resigned over obscene postings he made on Facebook about a woman who runs an online group for U.S. war resisters who wish to remain in Canada.

"Because of the repetition of comments I made before becoming a candidate, comments that I have already apologized for and profoundly regret, I can no longer continue as a candidate," Andrew McKeever said Friday in a statement released through the NDP.

The now-ex-candidate claimed he didn't want his situation to distract from the serious issues that need discussing before the Oct. 14 vote.

McKeever is the fourth NDP candidate to step down this election campaign. The other three were in B.C.

The controversy involving McKeever first surfaced late last month.

Bryan Ransom, the Liberal candidate in Durham, issued a news release on Sept. 25 that highlighted some of McKeever's remarks, which were made in July.

He said McKeever wrote in one posting to a woman: "Answer a direct f----  question you c---. I can guarantee, if I ever see you face to face I will make you squeal for the same authority you have such a baseless disdain for."

In a screen capture of McKeever's Facebook remarks made available by the Liberals, the ex-candidate also wrote: "There are bona fide (and by that I mean REAL) refugees out there. Not American crybabies that are trying to turn this country into a hotel.

"Maybe that's why Krystalline Kraus (sic) is so interested in this topic...having had no real chance to get l--- by any domestic male she needs to encourage others, new meat as it were..."

The Liberals issued a news release on Saturday claiming that the NDP had asked Krauss to stay silent.

"I don't like being silenced or manipulated by anyone in my life," Krauss said in a statement.  "I had asked for Mr. McKeever to resign and/or be removed by Mr. Layton but it was made clear to me that this would just not happen."

Liberal Leader Stephane Dion said in the news release that NDP Leader Jack Layton had failed to show leadership by not firing McKeever.

"How can Jack Layton claim he stands for women's rights when he allowed Andrew McKeever to stand as an NDP candidate for two weeks and took no action to fire him for his offensive behaviour. Instead of acting like a leader, Mr. Layton waited for the candidate to finally resign on his own," Dion said.

Durham riding is currently represented by Bev Oda, the current minister of international co-operation. She was first elected in 2004 and won in 2006 by almost 10,000 votes.

The Liberals held the riding from 1993 to 2004.

Durham riding lies east of Oshawa and north of Pickering-Ajax and Whitby-Oshawa ridings.