CAIRO (AFP) - Egypt’s top court postponed on Tuesday key rulings on the validity of the Islamist-dominated Senate and of the committee that drew up a controversial constitution approved by referendum last month. It will rule on the constitutional panel on February 3 and has referred the legality of the upper house to its adivsory body, the official MENA agency reported. Dozens of demonstrators had staged a sit-in in Cairo overnight outside the Supreme Constitutional Court (SCC) on the banks of the Nile, as riot police formed a cordon around the building. Two-thirds of the Senate, the 270-member upper house known as the Shura Council, were elected in a vote early last year, with one third appointed by President Mohamed Morsi in December.