The Assembly government in Wales has defended its decision to opt out of laws that are supposed to protect NHS doctors and nurses from violence.
Ministers in Cardiff, who have no power over criminal justice, have told Whitehall they will draw up their own policies, which may include free solicitors for hospital staff.
Lords and MPs want to add Wales to a Bill going through Parliament that currently only deals with NHS premises in England.
Doctors' and nurses' leaders have criticised the decision to leave Wales out and said NHS workers on both sides of the border need the same level of protection.
In October, Assembly Health Minister Edwina Hart promised a "zero tolerance" crackdown on violence in hospitals.
At the time she said she was not prepared to adopt a "softly softly" attitude and suggested nuisance patients could be banned.
Shadow health minister Jonathan Morgan said: "The Assembly gvernment's decision to pursue a Wales-only option on this issue is unacceptable and will inevitably lead to lower levels of protection for NHS staff in Wales."
Baroness Finlay, who is among Westminster politicians trying to amend the Criminal Justice and Immigration Bill so it applies to the Welsh NHS, said it may be the last such opportunity to help vulnerable health workers.