Deri made the announcement following a petition submitted by the city of Bat Yam against Deri, demanding that he appoint an investigative committee to examine dispersing the combined incomes of Bat Yam, Rishon LeZion, Holon and Tel Aviv among the four cities.
According to the interior ministry, preparations for the merger will begin in the near future, with the establishment of a government administration to oversee the endeavor.
If adopted, the unification would officially take place in 2023 following the election of one mayor. Until then, however, the city of Bat Yam will be subject to a special development program as a forerunner to the implementation of the plan.
According to Deri, "This is a significant step to strengthen the city of Bat Yam. I am considering adopting the recommendations of the professional committee that investigated the issue of uniting Bat Yam and Tel Aviv-Yafo at the end of an orderly process."
Deri added, "The Interior and Finance ministries will act together throughout the entire process to prepare the necessary infrastructure and mechanisms for the professional implementation of the unification, with an emphasis on services for residents.
"During the unification, full cooperation will be needed between the municipalities. We will ensure that the level of service residents receive will not be harmed, but will even improve. This is the first time a unification of this magnitude has been launched and we must act with great responsibility."
In response to Deri's comments, Bat Yam municipality issued a statement saying, "We demand an immediate solution to Bat Yam's budget, which is the result of a delay in the government's decision making.
"We demand from Finance Minister Moshe Kahlon an immediate solution in order to prevent damage to the city and its residents. Any decision will be made only by agreement by the majority of the residents of Bat Yam."
The Tel Aviv-Jaffa municipality said in response that "the position of the Ministry of the Interior, as published, means that the unification of the cities will not take place."
"(We) agreed to carry out a rapid merger to be completed by the end of 2018 and not by the end of 2023," they explained.
The Tel Aviv-Jaffa municipality summerized by saying that "this was a one-time opportunity in which the Tel Aviv-Jaffa municipality mobilized in a precedent-setting manner to quickly implement the union in order to hold elections for a united city in 2018.
"Anyone well-versed in this subject understands that postponing the Union for 2023 means that the Union will not be implemented. We regret this and can not take part in it."