The smallest coalition member, D66, withdrew its support from the coalition on Thursday following dissatisfaction over the tough stance of Rita Verdonk, the immigration minister, on the citizenship of a Somali-born Dutch politician.

Verdonk came under pressure to resign after she had threatened to strip Ayaan Hirsi Ali of Dutch citizenship for lying about her name, age and refugee status on arrival in the Netherlands in 1992.

D66, the smallest member of the centre-right government coalition of Jan Peter Balkenende that had been trying to boost its flagging profile before national elections in May 2007, pulled its support for the administration after the rejection of a bill of no confidence against Verdonk on Thursday.

"A rift was created with my party and I feel there is no other way but to withdraw support for this government," D66 party leader Lousewies van der Laan told parliament.