- 20 - In the event that works require final expropriation, the ownership laws in force shall be applied if no conciliatory settlement has been reached between the Ministry and the proprietor. Article 50 The Ministry may ask tree owners to cut branches extending over phone lines if the branches cause, or are likely to cause damage, to the lines. If the tree owner does not cut the branches, the Ministry shall cut them at his expense. Article 51 If the Ministry’s projects require the installation of a phone line on a public road whose sides have already been occupied by electricity lines, the owners of such lines shall remove them or reinstall them in such a technical way as to accommodate the Ministry’s project. Article 52 If any competent authority intends to install electricity lines beside or across phone line networks, it shall take, in agreement with the Ministry, the preventive measures necessary to secure the phone lines from the impact of electrical frequencies. Article 53 If any competent authority or local council intends to carry out constructions, digging, filling up or repair works on the public main road or sub-road beside or across phone line networks, they shall obtain a permit, in advance, from the Ministry of Telecommunications. Article 54