Polling booths opened early Wednesday in Dutch parliamentary elections after a deadlocked campaign between the governing Christian Democrats and the rival Labor Party, in a contest that will determine whether one of Europe's tightest immigration regimes gets even tougher or takes a softer approach. Prime Minister Jan Peter Balkenende, hoping to cash in on an economic turnaround despite his reputation for blandness and weak leadership, has consistently dominated the polls, and his Christian Democrats appear on track to become the largest party again. In four years in office, Balkenende has ushered his country, renowned for its hashish-selling coffee shops and legalized prostitution and euthanasia, through a tumultuous debate over immigration and the threat of Islamic terrorism following two political murders. Led by hard-line Immigration Minister Rita Verdonk, the government ended the Netherlands' traditional openness to foreigners and legislated more powers to the police and intelligence agencies. If Balkenende is returned to power, he likely will try to push through a new law banning head-to-toe Islamic robes such as the burqa. About 6 percent of the Dutch population is Muslim. With opinion polls swerving wildly in the final weeks, however, Balkenende is facing a strong challenge from Wouter Bos, leader of the opposition Labor Party, who hammered the conservatives for what he calls a heartless social policy but kept his criticism on immigration policy muted. With as many as 40 percent of 12 million eligible voters still undecided in the final surveys, it was impossible to forecast winners and losers. The only safe prediction appeared to be that many weeks of coalition-building will be needed after the vote is in, most likely between Balkenende and Bos. Balkenende also is credited with keeping an explosive situation under control after the murder two years ago by an Islamic extremist of filmmaker Theo van Gogh and avoiding widespread riots by disaffected immigrant youths such as those in France last year.