MPs have called for proposed corporate manslaughter offences to be tightened up, warning present proposals may help some big firms to avoid prosecution.
A number of rail crashes brought the issue into the spotlight
Current proposals may create "perverse" incentives to treat health and safety less seriously, a Commons report said.
It also warned the law focused on senior management failings rather than individual liability, which would allow top directors to avoid prosecution.
The proposed law aims to punish firms whose negligence leads to worker death.
There have been calls from unions for a new corporate manslaughter offence to be put on the books after a number of high-profile rail crashes, including at Potters Bar and Hatfield.
In the first instance no manslaughter charges were brought, and in the latter corporate manslaughter charges against Balfour Beatty were dropped.
A draft Corporate Manslaughter Bill was published after the General Election in May.
But a key clause which makes firms liable for worker deaths caused by "senior management" could lead to a "perverse incentive" for top bosses to delegate key health and safety decisions to more junior staff, the Home Affairs Committee warned.
To eliminate such a risk, a new offence of "secondary liability for corporate manslaughter" should also be introduced, the committee added.
The committee also called for a broad range of possible penalties for those found guilty of corporate manslaughter, to allow courts to reflect the individual circumstances of the death.
It also urged the government to include provisions for companies to be forced to pay compensation.
The report also criticised the government for an eight year delay in presenting the proposals to parliament, adding that the bill should be introduced during the current session.
"The reform of corporate manslaughter law is long overdue," said Home Affairs Committee chairman John Denham.
"The new Bill must be introduced this year, but it must take into account our recommendations if relatives of victims are not to feel cheated of justice in the future."