A new law to improve oversight over force used in mental health units has been given initial approval, after a man died when he was restrained in hospital.
Olaseni Lewis, 23, died in 2010 soon after being restrained by 11 officers in Bethlem Royal Hospital, Beckenham.
A misconduct investigation into his death was dismissed in October.
The Mental Health Units (Use of Force) Bill, known as "Seni's Law", passed its second reading in Parliament on Friday.
"If this law had been in place [then], Seni would probably be alive now," Ajibola Lewis, Mr Lewis' mother, said.
Under the new legislation, hospitals will be required to publish data on how and when physical force is used.
The bill would also make sure any non-natural death in a mental health unit triggers an independent inquiry.
Between 2000-2014, 46 mental health patients have died following restraint.
A Home Affairs Committee reported black people more commonly reported the use of force in mental health units.
People on the autism spectrum or with a learning disability were also identified as at extra risk from restraint.
Labour MP for Croydon North, Steve Reed, who tabled the bill, said: "Seni Lewis did not die in vain. We can honour his memory by making sure no one else suffers the way he did."
The second reading is the first time a bill is debated in parliament.
The bill now moves on to committee stage in the House of Commons, where detailed line by line scrutiny is carried out by a committee of MPs.