Labour MEP Cyrus Engerer has revealed he wrote a letter to his party's parliamentary group after it unanimously voted against holding a public inquiry into the death of Jean Paul Sofia.
In July, 40 MPs voted against a public inquiry into the Corradino construction site death after prime minister Robert Abela said a criminal inquiry into the collapse was sufficient.
However he back-tracked within days and following immense public pressure.
On Wednesday, the three-panel inquiry found that the 20-year-old worker died in an essentially unregulated construction site and the state must bear responsibility for that.
Engerer told his Facebook followers that after the vote he had written to the PL parliamentary group, questioning the exclusion of those who had a different opinion.
In the letter he "insisted that critical thinking and different opinions should be celebrated, not suffocated", he said.
"People were right not to understand how a whole parliamentary group had voted against a public inquiry into the death of Jean Paul Sofia," Engerer said, adding he had met several - especially young people - who questioned the lack of diverse opinion within the parliamentary group.
"'How can everyone think the same about something so wrong? How come no one represents my beliefs,' they had asked me," Engerer said.
"The closed manner in which politics is done in Malta is bothering many. People are losing trust in politics because of the antiquated manner in which big political parties operate, which is cut off from reality," the PL MEP said in his post.
He said that while unity was important, it did not mean that everyone should have the same opinion and that different opinions make a group much stronger.
"The sense of collegiality in a political party or parliamentary group, where everyone says the same thing is dangerous and laughable - because everyone knows that no two people agree on everything."
Engerer, who is the only Labour MEP to not reveal whether he will contest June's elections, also referred to his plenary address on Wednesday, when MEPs were discussing the assessment of the European Commission's 2023 Rule of Law report.
He told the European Parliament that some people in some European countries wanted to criminalise critical thinking.
"Voting for what you believe in is commendable even if you swim against the current, as is speaking when things are not right," he said. "After all, this is what the inquiry concluded on several entities that failed to speak up. This same failure should not persist in our politics and within our country's political parties."
Engerer has increasingly spoken out against some decisions made by his party colleagues.
Earlier this week he asked where "the political will" was around protecting minorities such as asylum seeker Kusi Dismark, who was returned to Ghana last week after 13 years living and working in Malta.
He has also said that there are politicians who support the introduction of abortion to Malta but are afraid to speak up.