The shadow home secretary David Davis today appealed to the police to take a "zero tolerance" attitude to crime.
Mr Davis's comments came after Warrington North MP Helen Jones demanded an inquiry into why teenager Adam Swellings was bailed hours before he took part in the gang murder of Garry Newlove in Warrington.
A jury at Chester Crown Court found Swellings, Jordan Cunliffe, 16 and Stephen Sorton, 17, guilty of Newlove's murder yesterday.
Davis said: "Garry Newlove's family must be suffering unimaginable grief. "This is the second time in as many days that we find a murder committed by a violent criminal released on bail.
"This tragic case is also a hideous demonstration of the failure to address drugs and alcohol-fuelled feral violence amongst teenage gangs.
"We need to see robust law enforcement - police back on the streets taking a zero-tolerance approach to crime, and honest and appropriate sentencing.
"We must also address the deeper causes - strengthening families, restoring school discipline and defeating the scourge of binge-drinking and drugs that feed the violence on our streets."
A spokesman for the Attorney General's office said: "Decisions on bail are a matter for the courts. We will consider the letter from Helen Jones MP when we receive it."
Warrington-man Newlove went out to confront a group of drunken teenagers who were vandalising his wife's car and a neighbour's digger on August 10 last year.
A court heard they responded by attacking the 47-year-old salesman and kicking his head "like a football".
Newlove, who was married to 44-year-old Helen, died in Warrington hospital two days later, a few days before he had been due to go on holiday with his wife and daughters.
After 10 days of deliberation, the jury found Swellings, from Crewe, and a 16-year-old and a 17-year-old guilty of his murder.
After the hearing, the two juveniles were named as Jordan Cunliffe and Stephen Sorton. A 17-year-old and a 15-year-old were acquitted.
Earlier this week, the body of Metropolitan Police inspector Garry Weddell, who was freed on bail ahead of his May trial accused of the murder of his wife Sandra, was found in woods in Markyate.
It is thought that the 47 year-old killed himself and his mother-in-law, Traute Maxfield, 70, whose body was found at her home 11 miles away. Both bodies had bullet wounds.
Weddell's wife was found dead in the garage of their family home in Dunstable on January 31 last year. Postmortem tests revealed the 44-year-old was strangled with a cable tie.
Speaking at prime minister's questions yesterday about the Weddell death, Gordon Brown, the prime minister, pledged: "If there are changes in the law necessary, we will make them."