The Dutch centre-right coalition battled to hold on to power in an election on Wednesday against leftist rivals who could water down pro-business policies and be more conciliatory on immigration.
Opinion polls put Prime Minister Jan Peter Balkenende's ruling Christian Democrats (CDA) narrowly ahead as voting began for the 150-seat parliament, largely because of an economic upturn under his coalition government.
But the opposition Labour party hoped for a late surge of support from people of immigrant origin, who are often underrepresented in opinion polls, and from the about 15 percent of voters who pollsters said were still undecided overnight.
The polls suggested neither Balkenende's alliance with the VVD liberals nor a Labour-led coalition with the Socialists and Green Left would win a parliamentary majority, making long coalition talks likely.
Balkenende, 50, underlined the Netherlands' economic improvement as he voted on a cool but sunny day. The first exit poll was expected to be released shortly before voting ends at 9 pm (2000 GMT). Official results will trickle in soon afterwards. Almost 40 percent of the about 12 million voters had voted by mid-afternoon, NOS public television said.
Final opinion polls projected the Christian Democrats (CDA) would win four more seats than Labour, which has narrowed the gap after a newspaper said last week Dutch intelligence may have mistreated prisoners in Iraq in 2003.
The election, originally scheduled for May 2007, was called after the centre-right coalition collapsed in June in a row over the government's handling of the disputed citizenship of Somali-born Dutch politician and Islam critic Ayaan Hirsi Ali.