Ayaan Hirsi Ali, the Somali-born Dutch activist facing death threats for her outspoken criticism of Islam, is to come under national police protection anywhere in the European Union, the top justice official in Brussels said tonight.

Franco Frattini, the European commissioner for justice and home affairs, told the Guardian that Hirsi Ali and any other persons facing threats to their lives because of their opinions or writings, would be guaranteed protection wherever they went in Europe and that the host country would bear the expense.

The issue was discussed at a lunch of all 27 interior ministers of the EU in Brussels today after being raised by the Dutch. Frattini said the ministers agreed and that the pact would be effective immediately based on "unanimous consensus".

Other European sources doubted whether such an agreement could be implemented so promptly.

British sources said a pan-European deal could not be "that simple" since there were cost and legal implications to authorising such special police measures.

"There can't possibly be political agreement on it," said an official.

Hirsi Ali went to the European Parliament two weeks ago to demand that the EU pay for her protection when living in the US.

Her colleague, Theo Van Gogh, was murdered on an Amsterdam street in 2004 after he and Hirsi Ali made a film, Submission, attacking Islamic treatment of women.

From then until last autumn, at a cost of around two million euros a year, she enjoyed special 24-hour Dutch police protection, even after she went to live in the US.

Last autumn the Dutch government withdrew the funding for the US operation and she returned to Europe.

Dozens of MEPs have signed a document of support calling on Brussels for pay for her protection round-the-clock wherever she may be.

"This is a new decision," Frattini said, declaring that no new laws were necessary to try to guarantee the safety of Hirsi Ali and others in similar situations. "If we need a law to guarantee the right to life, we're in a difficult position. We have the decision based on mutual trust."