Belfast-based law firm KRW is to take defamation action against the Secretary of State for Northern Ireland, Brandon Lewis, over comments made in relation to the UK Government's legacy bill.
The action is being taken over an online opinion piece by Mr Lewis, which comments on the Legacy and Reconciliation Bill and makes reference to the role of specialist law firms in legacy cases.
The action is being taken by all partners in KRW and by the firm as a corporate entity.
In a statement to the PA news agency, KRW partner Kevin Winters said that Mr Lewis had "attacked the work of specialist legacy lawyers dealing with Troubles-related cases".
"My colleagues and I can confirm we are taking defamation proceedings against him in both his personal capacity and as a Government representative.
"This is now the second such case we are bringing against the secretary of state.
"His comments come on the back of this Tory regime's ongoing drive to stop conflict bereaved victims getting access to justice through the courts.
"This latest attack on us is more than mere coincidence coming as it does after the second reading of its Legacy Bill.
"Not content with trying to lock up the courts, they now want to silence lawyers trying to keep those same courts open for conflict-affected families.
"There's an uncomfortable tone struck here which harks back to the toxic comments of previous Tory junior minister Douglas Hogg in 1989, when he accused some lawyers of being 'sympathetic to the IRA'.
"The offensive remarks also chime with the ongoing wider attacks by this Government on the important work of human rights lawyers generally.
"This latest diatribe betrays a mindset of trying to demonise anyone who dares to challenge state narratives on the past.
"They simply don't appreciate that we get our instruction from our clients. To that end, any attack on 'specialist lawyers' is an attack on the victims of the conflict."
A spokesman for the Northern Ireland Office said: "It would not be appropriate to comment on ongoing legal proceedings."
The UK Government's contentious Legacy Bill is currently going through Parliament.
It proposes a new approach to dealing with the conflict, with more focus on truth recovery rather than criminal justice outcomes.
Its most controversial aspects are the promise of immunity from prosecution for perpetrators who agree to provide information to a new truth body, and a move to end conflict-related civil cases and inquests.
The plans would also result in unsolved cases being subject to reviews undertaken by a new Independent Commission for Reconciliation and Information Recovery (ICRIR).
The Bill is a unilateral move away from the 2014 Stormont House Agreement, in which the UK and Irish Governments proposed a model that involved a new independent unit to reinvestigate unsolved murders.