Lawyer Andy Ellul will be co-opted to parliament after the Labour parliamentary group approved the nomination by Prime Minister Robert Abela.
The nomination was also approved by Labour's executive.
Ellul has been involved in several legislative reforms, especially in the social and family spheres.
Ellul was also the head of Malta's delegation at the Council of Europe's Lanzarote Committee, the party said in a statement on Monday evening.
Born in 1975, Ellul will be contesting the forthcoming general election on the 3rd and 4th districts.
He became a lawyer in 2007 and specialised in administrative law.
Together with his partner, TV presenter Claudia Cuschieri, he is the father to a 7-year-old son, Gianni.
Ellul thanked the prime minister for the co-option, saying he would "work tirelessly for the national good."
He will be replacing former MP Silvio Grixti who resigned from parliament in December after being interrogated by the police over an investigation into irregular medical sick notes. He was questioned by the police financial crimes investigation department and released on police bail, Times of Malta has been told.
Reacting to the news, the Nationalist Party said that this decision confirms how much the Prime Minister does not believe in the democratic process and wants to surround himself with people he has chosen and are more loyal to him.