Robin Cook, the Foreign Secretary, welcomed the German change of heart, saying it reflected the "gathering recognition that Turkey must be a part of such a European conference". "We have always taken the view that it is important to encourage those in Turkey who see Turkey's vocation as European," he added.
Ankara first applied to join the then EECin 1963 but most member states are deeply uncomfortable about encouraging its membership given Turkey's size, poverty, religious make-up and human rights record.
Resolving how to give Turkey the status it deserves within "the European family" without raising false hopes has become urgent now that EU membership negotiations with Cyprus are due to start in March. The Turks have threatened to annex northern Cyprus if negotiations proceed exclusively with the Greek Cypriots.
Mr Cook said Turkey would have to demonstrate "very substantial further steps" on its economy and human rights record but this would be easier through a process of dialogue.