The seventeenth anniversary of Pat Finucane's murder comes round in six days. When the defence lawyer was shot dead in front of his family back in 1989, there were almost immediate suspicions that there was more to his death than met the eye. Over the years, those suspicions have become well-grounded in fact. It is now more than two years since Britain's most senior policeman and a retired justice of the Canadian Supreme Court independently came to the conclusion that there was collusion between the UDA men who killed Mr Finucane and members of the security forces.

The next stage, at least according to Justice Peter Cory, was clear: there should be a public inquiry into the collusion surrounding the murder - the exact outcome for which Mr Finucane's family had been campaigning down the years. Since then, on the surface at least, very little has happened. There has been no apparent progress towards an inquiry - no panel named, no date set for a start. The exception is the passage of an important piece of legislation, one that currently stands between the Government and the Finucanes.

Tomorrow Mr Finucane's widow, Geraldine, and other members of the family will meet Secretary of State Peter Hain about the problems in setting up the inquiry.After campaigning for years for an inquiry, the family now find themselves in the curious position of opposing the one proposed by the Government. That is because the legislation passed to bring about the inquiry, the Inquiries Act, gives the Government unprecedented powers to keep aspects of the case secret.

Mr Hain also finds himself in a curious position. He has said there will be an inquiry under the Inquiries Act or "none at all". But the family's opposition has made setting up the inquiry difficult - so far the Finucanes have successfully discouraged judges around the world from chairing the tribunal - and could ultimately render it pointless. The Finucanes' refusal to cooperate would be a serious challenge to the inquiry's credibility even before it opened. The "none at all" option is equally unsatisfactory, in that it puts everything back to square one. Disturbing questions about the case remain unanswered and the Government looks as if it still has something to hide.

The family is not alone in having problems with the Act, which was rushed through Parliament last year. Justice Cory and the judges who chair the Bloody Sunday Inquiry have also questioned it. The Government says the Act makes public inquiries more focused; in the wake of the Bloody Sunday Inquiry's huge costs, it applies a brake to funding.

But the Act is controversial because it has made an important shift in powers: now the Government adopts the role of player and referee in the operation of an inquiry. Where the chairman of a tribunal or a High Court judge would determine whether sensitive information given to the inquiry should be secret, now that power lies with a Minister. What a Minister wants excluded is automatically excluded; he or she may also stop the inquiry at any time and edit the inquiry's final report.

The Finucanes argue that this takes away the independence of the inquiry, and they are not alone. Last week, David Wright, the father of loyalist Billy Wright, took High Court proceedings against the use of the Act in the inquiry into his son's murder in the Maze Prison.

National security is an important factor in the Finucane case, at the very least in terms of exposing the practices of intelligence agencies. After all, it was an Army agent that supplied the information that led to Mr Finucane's murder. It was a police agent who supplied the guns. The man who organised the killing is believed to have been yet another agent, and one of the triggermen was later recruited as a police agent, in spite of making a confession to detectives.

The Finucanes have not disputed that national security is a genuine consideration in an inquiry, but they point out that such concerns have been adequately protected by the legislation that has been in place for more than 80 years.