The British government was today accused of an attack on democracy after it published draft legislation on the conduct of inquiries.
The new laws will give ministers the power to hold public inquiries in private on the grounds of national security.
They were flagged up by Northern Ireland Secretary Mr Paul Murphy when he announced the setting up of an inquiry into the murder of Belfast solicitor Pat Finucane.
SDLP Policing spokesman Mr Alex Attwood said the draft bill which was published today confirmed his party's worst fears.
"This legislation totally undermines the independence of inquiries. In reality, it ends public inquiries as we know them," he said.
"In future they will be government-controlled and government-censored. This is an assault on democratic values."
The West Belfast MLA said the legislation would affect all inquiries to be held in Northern Ireland and Great Britain.
"The SDLP is writing to all members of the House of Lords and House of Commons to express our opposition. We hope to build a coalition against this attack on openness, democracy and transparency," he added.
When the inquiry was announced in September, the Finucane family expressed serious concerns about its independence.
They threatened not to co-operate with the inquiry if the British government's proposals were unacceptably restrictive.
Mr Finucane (39) was shot dead in front of his family at his north Belfast home by members of the Ulster Defence Association in February 1989.
The murder was one of the most controversial of 30 years of violence in Northern Ireland, leading to allegations of collusion between loyalist paramilitaries and members of the security forces.