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Dutch Prime Minister Mark Rutte — known by many as "Teflon Mark" because scandals and criticism tend to slide off him — is showing signs of wear just weeks before a national election.

Rutte faced a bruising debate in Parliament on Thursday as opposition lawmakers called his prized reputation for honesty into question. On Friday, he took to the letters page of a national newspaper to defend his attempt to woo voters away from a popular, anti-Islam firebrand.

The problems, which include one of his Cabinet ministers resigning under a cloud this week, overshadowed recent economic figures showing a buoyant economy and low unemployment in the Netherlands, where Rutte has been prime minister since October 2010.

"The Liberal Party is in stormy weather," University of Amsterdam political science professor Meindert Fennema said of Rutte's party. The scandal that led to a minister's resignation Thursday night "exploded in (Rutte's) face, which makes him look very unreliable."

The prime minister's troubles come as he and his campaign team gear up for one of the toughest challenges of Rutte's long political career — beating populist Geert Wilders in the March 15 parliamentary election.

Wilders' unfiltered rhetoric slamming Islam, migration and the European Union has resonated in this nation of 17 million and made him a serious candidate to win the popular vote. It also has alienated many mainstream parties, meaning it would be tough for him to form a majority coalition to take power even if he wins.

Rutte faced criticism this week after his campaign took out full-page advertisements in several national newspapers that used language similar to Wilders' in what was clearly an attempt to win over voters from Wilders' Party for Freedom.

The ads had the prime minister saying, "We have to actively defend our values" against people who refuse to integrate or act antisocially. "Behave normally or go away."

In an unusual step following the ads' appearance Monday, Rutte sought to clarify his message. In a letter to the national De Volkskrant newspaper on Friday, he said his statements were not aimed at a particular group in the Netherlands.

"For me, it is not about whether you are white or black, Islamic or Christian, gay or straight, a migrant or somebody who has been here for generations," Rutte wrote, adding that his message was an appeal for people to "behave normally."

Columnist Sheila Sitalsing wrote in the same edition of the newspaper that scratches are appearing in the premier's non-stick coating.

Radboud University political science lecturer Koen Vossen said Rutte's appeals show he is prepared to go to great lengths to win over voters from Wilders' party, known by its Dutch acronym PVV.

"He is doing a dirty job that left-wing politicians are not prepared to do," Vossen said. "That dirty job is, of course, trying to integrate PVV voters or those who want to vote PVV into a more mainstream party."

One of Rutte's strengths has been his reputation as an honest leader, but opposition lawmakers are working to chip away at his credibility as the election approaches.

The tough debate Rutte had to sit through on Thursday dealt with a long-running scandal involving a deal made by prosecutors with a drug trafficker in 2000 and ongoing efforts by journalists to reveal all the details of the agreement.

The debate led to the resignation of Rutte's Security and Justice Minister Ard van der Steur amid allegations — which Van der Steur rejected — that he assisted a previous minister in trying to conceal information about the deal from Parliament.

The resignation spared Rutte from more questions about his own role in the scandal, but the political fallout may damage him anyway.

Wilders used the debate to openly attack Rutte's credibility, calling him, "by a long way, the most untrustworthy premier the Netherlands has had in a long time."

Rutte will be hoping the accusations don't stick.