Write an Legal Opinion based on the given facts.

The City of Manila intends to construct a new building over a lot in Delpan, Tondo, which will be used to house the informal settlers in Baseco Compound. In initiating such project, the City of Manila, thus, needs the following parcels of land: (1) a two-hectare land covered by TCT No. T-12345 in the name of spouses Juan and Juanita Bonanza, and (2) a three-hectare land covered by TCT No. T-54321 registered in the name of Reynaldo Dela Cruz. The zonal value of the lands located in Delpan, Tondo is P10,000.00 per square meter, although the zonal valuation was last updated in 2014. Upon investigation of the City Engineering Department of the City of Manila, however, it turned out that the land covered by TCT No. T-12345 was mortgaged by Spouses Juan and Juanita Bonanza to Bank of the Philippine Islands under entry number 12031991, and to the Philippine National Bank under entry number 03121991. There is also an uncanceled encumbrance over TCT No. T-12345 with entry number 19911203 in favor of Jose Protacio executed in January 2000 when Spouses Juan and Juanita Bonanza obtained a loan from him on the same year, although the loan was already paid. It was further found out that Jose Protacio died in May 2015 and was survived by his heirs, namely, Andres Protacio, Emilio Protacio, and Gabriela Protacio. As to the land covered by TCT No. T-54321, it appears on the title that the same is mortgaged to Security Bank under entry number 19910312. It was further found out that the land covered by TCT No. T-54321 was already sold by Reynaldo Dela Cruz to Megawide Corporation, although the title of Reynaldo Dela Cruz was not yet cancelled and transferred to Megawide Corporation. Additionally, when the engineers of the City of Manila made an ocular inspection of the properties that they intend to use for the project, they discovered that two (2) families were occupying certain portions of the lands covered by TCT Nos. T-12345 and T-54321, these are the families of Lilia Bahing and Lilo Morano. Confused as to whom they will make the letter-offer for the expropriation of the land, the engineers of the City of Manila sent everyone a letter-offer for the purchase of the land. All of the letter-offers were rejected by the concerned persons, thus, the engineers of the City of Manila wrote a letter to the Legal Department of the City to render an opinion as to the proper course of action. In response, the Legal Department recommended the filing of an expropriation complaint in order to take the properties covered by TCT Nos. T-12345 and T-54321. However, since the zonal valuation of the lands in Delpan, Tondo is outdated, and considering the requirement under the law that the basis of zonal valuation should be the most recent ones, meaning at least three (3) years at the time of the filing of expropriation, some of the legal staff in the Legal Department are unsure as to whether there is a need to include the Bureau of Internal Revenue as party to the looming expropriation case