House lawmakers are planning to debate a bill intended to tighten Massachusetts' gun laws.

The bill up for debate Wednesday would require police chiefs to give reasons for denying gun licenses to individuals seeking them. Those denials would have to be based on public safety and could be appealed.

The bill would also create a web-based portal within the state Executive Office of Public Safety to allow for real-time background checks for private gun sales.

It would also stiffen penalties for some gun-based crimes and create a firearms trafficking unit within the State Police.

House Speaker Robert DeLeo says the bill is fair.

Gun rights advocates say they are concerned House lawmakers would have less than 24 hours to read the final version of the bill, which was released Tuesday evening.