@Walter Hinteler,
Walter, as usual, you failed to give the whole story.
Ynetnews.com published the following:
Foreign Ministry Spokesman Yigal Palmor said in response that Israel's policy for the past three years has been not to allow high-ranking politicians into the Gaza Strip.
"This is not a personal decision against Niebel, who is a wanted guest. The project he wishes to promote is also important and positive in our eyes. Hamas uses such visits in a manipulative fashion in order to show that its diplomatic isolation in the international arena has been broken," said Palmor.
"If the Germans only wanted to promote a water purification plant, what would a visit to Gaza help? If there are problems, they have to speak with us. If they wanted to know what is happening with their taxpayers' money, Germany could send a clerk or an office manager, not a politician, and we would not deny him entry. If we were to let Niebel enter, how could we say 'no' to ministers from other countries?"