The Paddington crash prompted calls for a law change

The omission will disappoint campaigners who have been pushing for a tougher regime in the wake of the Paddington and Hatfield rail crashes.

The government had been expected to promise concrete measures next year.

A draft bill is now expected in early 2003, but it will not form part of the year's legislative programme.

"They should have introduced a new law on corporate manslaughter, a manifesto commitment," said Derek Simpson, General Secretary of the Amicus trade union.

Guilt test

The government first promised to crack down on "corporate killing" in 1997.

Home Secretary David Blunkett outlined details of draft proposals in May, stirring hopes that he would attempt to push through new laws next year.

At present, businesses can only be convicted of manslaughter if it can be shown that negligence by a senior manager - or "controlling mind" - was to blame.

This means that large companies, where lines of responsibility are harder to establish, usually escape prosecution.

To date, only five companies - all of them small businesses - have been found guilty of manslaughter.

The only other way of penalising firms responsible for fatal accidents is to fine them under health and safety rules.

Hatfield trial

The government has been considering legal changes under which firms could be found guilty of manslaughter if deaths were caused by general "management failure."

Earlier this year, Network Rail and engineering firm Balfour Beatty were charged with corporate manslaughter over their role in the October 2000 Hatfield rail crash.

However, their trial will not be affected if the law changes, as any new measure would not apply retrospectively.

Tougher corporate killing laws could also be used to take action against firms whose employees die as a result of inadequate safety measures.