In the ongoing battle over Jerusalem's borders, an Interior Ministry planning committee on Tuesday decided to postpone a ruling regarding a controversial building plan that would expand the city westward. The committee will reconvene in a month. Environmentalists argue that the project will irrevocably damage the landscape. The much-debated Safdie plan - named after Moshe Safdie, the internationally renowned architect who designed the original plan - would see the construction of 19,000 housing units on more than 26 sq. km. of natural woodlands and forests in one of the largest construction projects ever proposed in Israel. The plan, which has been on the drawing board for much of the last decade and which has the backing of the Jerusalem Municipality, gathered steam last month after an external consultant appointed by the ministry to study it gave his approval. Proponents argue that the plan is essential for the natural growth of the congested city, to ease its notoriously high real estate prices and make room for new immigrants. But a string of environmentalist groups say it will irrevocably alter historic vistas and destroy the remnants of green spaces around the city. "This plan is a death blow and heart attack for the city of Jerusalem," said Anat Assal, spokeswoman for the Jerusalem branch of the Society for the Protection of Nature in Israel. In addition to the environmental damage, the coterie of green groups - called the Sustainable Jerusalem Coalition - point to a study they commissioned which indicates that at least 60,000 housing units could be built within Jerusalem over the next two decades. They argue that expansion westward is unnecessary and will lead to the neglect of the city itself. The coalition, consisting of more than 50 groups, includes SPNI and the Israel Union for Environmental Defense. The groups, who were not invited to Tuesday's critical hearing on the plan, will hold a protest outside the Interior Ministry offices in the government compound in Jerusalem on Tuesday morning. Assal said that the group had amassed 16,000 signatures of those opposed to the plan, and that their voice has not been heard by city and state planning officials. In contrast, the city said the plan was its savior. "The plan, which is of primary importance to saving the city, will ensure a future for the city and prevent emigration and the continued increase in the price of housing," a spokesman for Mayor Uri Lupolianski said Monday in a written statement. On the political front, the plan pits Lupolianski and former Jerusalem mayor and current Vice Premier Ehud Olmert - who support the project - against Environment Minister Shalom Simhon, Deputy Minister Michael Melchior (Meimad) and at least 12 MKs, including Yuri Shtern (Yisrael Beiteinu), Omri Sharon (Kadima) and Roni Bar-On (Kadima). The state's expected decision to expand Jerusalem westward comes against the backdrop of the government's recent decision to freeze a decades-old plan to expand the city eastward to Ma'aleh Adumim. That politically-sensitive plan, commonly known as E1, was frozen earlier this year due to American pressure. The government's decision to indefinitely freeze E1, officials said, led the external consultant to endorse westward expansion in its stead as part of an ongoing effort to buttress the city's dwindling Jewish population.