The commission criticised most stages of emergency care
A public inquiry could be ordered into Stafford Hospital after it was criticised for "appalling" failings, the Law Society said.
Poor standards in emergency care at the hospital meant patients died needlessly between 2005 and 2008, the Healthcare Commission reported on Wednesday.
The Law Society's Malcolm Fowler said the circumstances showed many features that could lead to a public inquiry.
Health Secretary Alan Johnson is reviewing the trust's emergency care.
About 400 more people died at Stafford Hospital between 2005 and 2008 than would be expected, the Healthcare Commission said.
It said that, while it was impossible to blame all of the extra deaths on the hospital's care, some patients would have died as a result.
The commission reported deficiencies at "virtually every stage" of emergency care and said managers pursued targets to the detriment of patient care.
Mr Fowler said it could lead to a "wide-ranging and independent" public inquiry chaired by a judge.
"I would be rather surprised if the aggrieved parties - as they see it - won't start clamouring for a public inquiry," he said.
"And I recommend, if they haven't done already, they go to their constituency MPs."
He also said it was possible that criminal charges could be brought against the hospital or individuals, but said this was very complicated and would "take a lot of unravelling".
Mr Johnson has said a review of Mid Staffordshire NHS Foundation Trust, which runs the hospital, would be carried out, focusing on the years 2002 to 2007.
He said there would also be an independent review of the trust's current emergency care.