Geert Wilders, who says he will found a party to clamp down on Muslim "militants", would win 26 of the 150 seats in parliament if an election were held now, against 25 for Prime Minister Jan Peter Balkenende's Christian Democrats (CDA), according to a poll published on Sunday by the ANP news agency.
Wilders is a member of parliament who was forced out of the VVD for refusing to back Turkey's bid to join the EU.
He says Islam is incompatible with democracy and wants new curbs on immigration, particularly from Turkey and Morocco.
Many see him taking on the mantle of the anti-immigration populist Pim Fortuyn, whose party soared to second place in a general election days after he was murdered in 2002.
This month's murder of Theo van Gogh, who had directed an insulting film about violence against Muslim women, has heightened ethnic tension in the Netherlands and led to a series of tit-for-tat arson attacks against mosques and churches.
Around 10% of the Dutch population are defined as non-Western foreigners - many of them Muslim Moroccans and Turks.
Alongside an increase in racist violence, there are growing demands for better integration of immigrants into traditional Dutch society and values.
The poll by the Maurice de Hond group had all three coalition parties - the CDA, the VVD free-market liberals and the centrist D66 - losing support since the 2003 election. The opposition Labour party (PvdA) topped the poll with 52 seats.
Wilders has said he plans to form a liberal-conservative party to contest the next election, due in 2007, together with Bart Jan Spruyt, the director of a conservative institute.