Borghezio, who sits in the nationalist Europe of Freedom and Democracy (EFD) group in the EU assembly, hopes his crusade will lead to the establishment of a European 'scientific UFO centre'.
The centre would be tasked with carrying out "analysis and dissemination of the scientific data gathered to date by various European bodies and governments".
As of yesterday (6 July), 23 MEPs had signed Borghezio's declaration, which was submitted on 14 June.
If it is signed by a majority of the EU assembly's 736 MEPs before it expires on 14 October, European Parliament President Jerzy Buzek will forward the declaration, together with the names of the signatories, to officials in the European Commission and the European Council as well as national governments.
Lobbying the EU to release its UFO files, Borghezio calls "for public archives on UFOs to be opened up and for records to be declassified by the member states, thus providing the public and the mass media with access to the full range of documentation on the subject".
Asked what he was hoping to achieve with the declaration, the Italian told EurActiv that he was looking to send "a strong warning" to EU member states that "they must make available to science all the documents on UFOs which are now withheld" and claimed that "transparency requirements" were what motivated him to take action.
Asked whether he believed in the existence of UFOs and alien life himself, Borghezio replied: "I think it is possible."
In the declaration, the MEP claims that "many members of the scientific community have been looking into the issue of UFOs and have denounced the systematic covering up of information on the subject".
He points to a 1978 United Nations summit in which "the 33rd General Assembly [...] formally recognised UFOs as a valid issue" at political level.
The Italian goes on to argue that "a study of the material collected by the governments of all […] member states would have major scientific and technological spin-offs".
Borghezio expressed hope that his declaration would prove a success. "I'm getting support from MEPs, newspapers and television stations from different countries," he told EurActiv.