A candidate for the New Democratic Party in London, Ont., has caused a stir by withdrawing from the election and telling his supporters to vote Liberal on election day.

NDP Leader Jack Layton quickly said the party would have a replacement nomination "within 48 hours."

Ryan Dolby announced he was pulling out of the election campaign during an interview with a local radio station on Wednesday. He said he will instead support Graham Warwick, the Liberal candidate for his riding of Elgin-Middlesex-London.

"I think it's the best decision on behalf of my family, my community, and my country to do whatever I can to make sure there isn't a Conservative victory, especially in this riding," he told AM980.

The move contradicts one of Layton's central messages -- that his party can unseat the Conservatives.

Dolby said he wanted to avoid splitting the vote, which would pave the way for Conservative candidate Joe Preston to take the riding on May 2.

In the 2008 election, Dolby won 9,135 votes for the NDP. He finished third behind Liberal Suzanne Van Bommel, who took 11,169 votes. Preston was re-elected with 22,970 votes.

Layton didn't appear phased by the news, said CTV's Richard Madan, who accompanied the NDP leader on campaign stops in Ontario on Wednesday.

"He wanted to essentially brush it under the rug and just move on with his campaign," Madan said.

Layton has been asking voters to defeat the Conservatives by supporting his party over the Liberals. It appears Dolby held the opposite view.

"Voters are going to take a look at Mr. Ignatieff and they'll take a look at me, and they'll make a decision about who is really going to stand up to Mr. Harper," Layton said at an event in Brampton, Ont.

Ignatieff was happy to hear of Dolby's withdrawal, saying that it showed the Liberals are the only party that can realistically provide an alternative to the Conservatives.

"This is an NDP candidate in a riding who looks at a great Liberal candidate, Graham Warwick, and understands something I think a lot of NDP voters are understanding," Ignatieff said.

"If you want to replace Stephen Harper, the place to go, the place to vote is to come into that big red tent at the centre of Canadian political life."

Dolby said he did not consult New Democrat officials about the move.

"I want to make sure we get a progressive MP -- one that cares about improvements to the Canada Pension Plan, improvements to employment insurance, believes in democracy instead of contempt, and believes in sustainable job creation instead of building more prisons," he said.

"I know Graham Warwick has the same values that I do."

Layton said there are essential differences between the NDP and the Liberals, who he said tend to steal his party's ideas and then fail to implement them once elected.

"They do tend to make announcements that are progressive, and then turn around and go the other way," Layton said.

With files from The Canadian Press