By Jonny Dymond BBC Istanbul correspondent

Mr Erdogan is expected to raise EU membership

In the minds of many in Turkey, there is little doubt that France is the member state which is most openly hostile to Turkey's membership bid.

Some senior French politicians have publicly opposed Turkey's membership.

But Turkey hopes to get assurance from the French that its bid will be judged on the right criteria.

In Turkey, few have forgotten the words of former French president and architect of the EU constitution Valery Giscard d'Estaing.

He said bluntly that Turkey was not European and that if it joined the EU, it would be the end of the union.

No French politician in office has been so openly hostile to Turkey's bid. But the concern is that Mr Giscard d'Estaing voices publicly what many in France believe privately.

What Turkey wants from the visit is pretty plain - an assurance from the French government that its bid will be judged on the so-called Copenhagen criteria of political openness and accountability, rather than on the rights or wrongs of admitting a large, poor, Muslim state into the union.

Analysts here believe that the visit would not have been organised had France not been prepared to make encouraging noises.