What is the ruling on performing Friday prayer in a new mosque built close to an old mosque (approximately 200 meters away), knowing that some scholars deem the Friday prayer invalid therein because it was not transmitted from the Salaf that multiple Friday prayers were held in one town except out of necessity, and that prayer in it is not valid unless the old mosque and its surroundings are full?

The default is for Friday prayer to be established in one mosque, in order to achieve the objectives of gathering and fostering harmony among Muslims. It is not permissible for there to be multiple Friday prayers in a city except out of necessity, such as the mosque being too small, or too far away, or fear of sedition. The statement of one who says: "It is not permissible to abandon prayer in the old mosque to pray in the new one" is not absolute; if the benefit necessitates moving to the new mosque because the old one is too small, then that is permissible, as Sheikh Ibn Baz has ruled.