The internal market committee is set to debate a raft of amendments to draft laws approved by member states last week.
The draft, the second revision of the 1991 EU firearms directive, includes stricter rules on buying and owning semi-automatic weapons, steps to stop deactivated guns being put back into circulation and improved tracing of trafficked weapons.
They set minimum standards for member nations to respect, but do not stop them from putting tougher laws into place.
The proposal must be negotiated with Parliament before it can become law.
The parliamentary debate on Tuesday comes in the wake of the Brussels and Paris terrorist attacks and after the latest mass shooting in America at the weekend in which at least 50 people were killed in an Orlando night club.
However, the Commission - backed by the Dutch EU Council presidency - faces a battle in winning parliamentary support for its plans.
UK Tory MEP Vicky Ford, who is steering the legislation through Parliament and has tabled several amendments, has branded the Commission's proposals as "poorly drafted and impractical".
She said the move will have "unintended consequences" for museum owners and collectors, sporting organisations and groups such as the Countryside Alliance in the UK.
Austrian EPP group member Othmar Karas has also voiced concern, saying the draft "creates a lot of uncertainty" among licenced gun owners.
The gun lobby has predictably mounted a fierce campaign designed to drastically water down the draft.
EU governments reached agreement on their position on the proposals on Friday, although some member states with a lot of hunters, including Poland and the Czech Republic, opposed it.
The Czech Republic, with a population of 10.6 million people, has about 775,000 legal guns and rifles.
Malta and Slovakia, the next presidency incumbent, both want the draft amended.
The focus now shifts to Parliament for it to work out its position ahead of final votes in committee and plenary on 14 July and 22 November respectively.
The Commission insists its proposal will "better track" legally held firearms, strengthen cooperation between member states and ensure that deactivated firearms are rendered inoperable. It says the move will better protect citizens and prevent criminals and terrorists from accessing weapons.
Speaking in November, Dimitris Avramopoulos, the European Commissioner responsible for migration, home affairs and citizenship, said the firearms package was "proof of the Commission's determination to address the new reality we are confronted with."
On Friday, Dutch Justice Minister Ard van der Steur said the result will mean that "the risk of legal firearms finding their way to the illegal market is reduced."
Emily Haber, secretary of state in Germany's Interior Ministry, said, "We have set standards, and there will now be no more weapons that can be traded without being registered."
French interior minister Bernard Cazeneuve said the agreement "will allow the security of citizens to be improved thanks to a stronger legal framework and the increased traceability of firearms at the European level."
Gun ownership is a cultural norm in some European countries and seen as sacrosanct. Countries like the Czech Republic oppose the revision because they say it obstructs legitimate gun owners.
But the decision to ban semi-automatic and automatic multi-round weapons faces a significant backlash in Parliament.
On Monday, an ECR group spokesperson told this website "The Commission proposals were badly drafted. The law needs to protect legitimate users while keeping guns out of the hands of terrorists and criminals."
Elsewhere, the European Federation of Associations for Hunting and Conservation has called on the Commission to "respect the rights of hunters and sport shooters, who represent the largest group of legal and responsible users of civilian firearms in the European Union and who are among the most intensely controlled and law abiding social groups in the EU."
It is "very much concerned" the Commission presented its proposal without an impact assessment, adding, "this makes it impossible to estimate the consequences of the proposed amendments on criminal activities, as well as on the lawful use of firearms.
"The proposed ban of certain semi-automatic firearms is unjustified and the Commission will have to explain how owners will be compensated in the case of a confiscation of these firearms."