Apparently the SNP will step forward today and make a bid to be the official opposition party on the grounds that the parliamentary Labour Party is shambolic at the moment and not in a fit state or "prepared... to assume power". According to the news report I read, this is a requirement of the opposition laid down in the Parliamnetary rule book, Erskine May.
Corbyn, meanwhile, insists that the vote of no confidence by MPs has no constitutional legitimacy. I'm sure that, technically, that is correct, but so, it would seem, is what the SNP is saying.