MANILA, Philippines -- Militant party-list representatives and a public transport group asked the Supreme Court on Wednesday to nullify the Land Transportation Office?s radio frequency identification system for being unconstitutional.

Bayan Muna Representative Satur Ocampo and Teddy Casiño, Gabriela Representative Liza Maza, Anakpawis Representative Joel Maglunson and the Pagkakaisa ng mga Samahan ng Tsuper at Operators Nationwide (Piston, Unity of the Organization of Drivers and Operators Nationwide) filed a 56-page petition for a temporary restraining order and prohibition on the implementation of the RFID system.

The LTO is expected to implement the RFID?an identification and tagging system for motor vehicles?in January.

The petitioners alleged that the Department of Transportation and Communication and the LTO violated the Government Procurement Act because the project did not undergo public bidding.

They also alleged that the project was unconstitutional because it usurped Congress? legislative power.

The petitioners cited the absence of a law providing for the installation of radio identification tags on all motor vehicles as a requisite for registration and re-registration.

Another constitutional issue besetting the project, according to the petitioners, is the potential intrusions to a motorist?s right to privacy that the system allegedly poses.