The SDLP has refused to comment on the current crisis which is engulfing the Labour Party and threatening its leader.
The two parties have long enjoyed an affiliation, and SDLP MPs take the Labour whip in Westminster.
The nationalist party’s silence comes as an extraordinary rebellion among Labour MPs has left veteran socialist Jeremy Corbyn casting around for allies, after a long string of his colleagues quit their shadow cabinet positions in a bid to force him out.
Asked by the News Letter “should he stay and fight or should he go for the sake of the party?”, the SDLP’s central press office responded simply: “The SDLP will not be giving any comment regarding Jeremy Corbyn.”
At the weekend, Mr Corbyn’s allies insisted that trade unions can broker a peace deal to end Labour’s meltdown as they claimed the leader is the victim of a “political lynching”.
Former leaders have warned the party must have “credibility” as an Opposition and insisted party rules mean he must quit.
But Len McCluskey, the Unite union leader, told the BBC: “This has been a political lynching of a decent man, undermined, humiliated, attacked, in order to push him out.
“And here’s the truth. It’s failed. The coup has failed. Jeremy Corbyn is made of stronger stuff, he is a man of steel and he has made it clear that he will not stand down.”
The trade unions can “broker a peace”, Mr McCluskey said as he urged potential challengers Angela Eagle and Owen Smith to step back.
But party grandee Neil Kinnock said support for Mr Corbyn is seeping away in the country and there is “no basis” on which he can stay in post.
He said Mr Corbyn would need to secure backing from more than 50 MPs if he wanted to fight a leadership challenge.
For details of some of Mr Corbyn’s past dealings with republicans, see this link.