Latest developments:
Shadow Scottish secretary Ian Murray announced his resignation from the shadow cabinet.
In a letter addressed to Jeremy Corbyn, he said the leader of the Scottish Labour Party, Kezia Dugdale is doing "an excellent job but needs a strong UK Labour Party to support her".
Mr Murray also said he felt the way some of his colleagues have been treated "is unfortunate".
"I will therefore return to the backbenches to serve my constituents and fight Scotland's corner from there," he added.
Mr Murray joins Heidi Alexander and Gloria De Piero in stepping down in the wake of the EU referendum, while Hilary Benn was sacked.
As the only Labour MP north of the border, means the replacement shadow Scottish secretary will have to be a non-Scottish MP.
The leader of the UK's biggest trade union has said the country is 'riven' as a result of the EU referendum.
Len McCluskey told ITV News that the trade unions can help broker a peace deal and reunite the party now the "coup has failed".
Labour leader Jeremy Corbyn said he would 'reach out' to MPs that oppose his leadership but said they should 'respect democracy'.