Israeli Prime Minister Menachem Begin plans to move his office soon to Arab East Jerusalem despite worldwide opposition, Natityahu Schmulewitz, director general of the prime minister's office, said on Israel Radio Sunday night. This was the first clear indication that the prime minister intended to go ahead with the move. However, the decision to move must be made by the Cabinet. A bill to declare Jerusalem the eternal united capital of Israel is scheduled to have its first reading in the Knesset (parliament) Wednesday. But with the Knesset recess due at the end of the month, it has almost no chance of becoming law until the autumn session.