The SDLP are planning to lobby MPs in Westminster today to oppose legislation affecting an inquiry into the murder of Belfast solicitor Pat Finucane.
Mr Alex Attwood is meet MPs from all parties at Westminster as part of briefings about government plans for an inquiry into the 1989 murder.
After a meeting with Prime Minister Tony Blair yesterday, the family of Pat Finucane threatened to boycott an inquiry into allegations that members of British army intelligence and the Royal Ulster Constabulary colluded with loyalists in his shooting.
Mr Finucane's widow, Geraldine, and son Michael, have been pressing for an independent public inquiry. However, Mr Blair was only able to say that the inquiry would be as open as possible, with some evidence possibly being taken behind closed doors in the interest of national security.
Pat Finucane was shot dead in front of his family in North Belfast in February 1989 by the UFF. In September Ken Barrett (41), received life imprisonment after he admitted having a role in the murder.
Following the conviction of Barrett, the British government announced an inquiry would take place but said new legislation was required to enable the tribunal to deal with sensitive issues of national security.
The Finucane family have raised concerns about whether the legislation is necessary. After their meeting with Mr Blair, Michael Finucane said although the Prime Minister was sympathetic, he had not allayed their concerns.
"Ultimately the inquiry is not satisfactory, even after all the hard work he has had to put in, then we may have to withdraw and may have to refuse to co-operate," he warned.
"I think that would be an extremely unfortunate decision to have to make and very much hope that we do not have to take that decision.
"But we had to leave the Prime Minister in no doubt that if we are put to the sword we will walk away."