The Labour Party executive agreed to change the statute to allow MPs to contest for the deputy leader role on Friday.
The vote was taken at an extraordinary general conference at the Labour Party headquarters.
Sources told Times of Malta the majority of delegates voted in favour of the statute change, while six voted against it.
Previously, the party statute said a person who forms part of the party's parliamentary group, which includes MEPs, is not allowed to submit their nomination for the post.
The change will likely pave the way for MEP Alex Agius Saliba to run for the job, who earlier this week teased he would possibly contest for the role.
His announcement came after VCA chairman Jason Micallef dropped out of the race.
The race is to fill former deputy leader Daniel Micallef's post, who resigned from the role back in June.
The past few days have seen the announcement of several resignations in the office of the prime minister.
Robert Abela's former chief of staff Glenn Micallef resigned in June, before being nominated as Malta's pick for European Commissioner.
Aleander Balzan, one of the PM's policy advisors, also resigned last week, followed by the PL's head of communications Ronald Vassallo, who resigned on Thursday.