Only Scots Labour MP Ian Murray quits shadow cabinet
Labour's only MP in Scotland, Ian Murray, has resigned from his position as shadow Scottish Secretary.
Speaking live on the BBC's Sunday Politics Scotland programme, he said he had just written to Labour leader Jeremy Corbyn.
Mr Murray said matters had been brought to a head by the result of the EU referendum.
He believed it was important for Labour to be a strong opposition and ready to get back into government.
He said: "We've gone through an incredibly difficult time, not just in the party but since the EU referendum result on Friday morning.
"The Labour Party has to be a strong opposition and a broad coalition in order to get back into government."
Mr Murray said Jeremy Corbyn was not the right person to lead a Labour revival.
He said: "He's a decent human being, a lovely man who I get on incredibly well with. But he just can't lead the Labour Party and I don't think the public think he can be Prime Minister."
Scotland in Europe
Speaking now as a backbench MP, Mr Murray said the Scottish Labour Party would support efforts to protect Scotland's position in the EU.
He added: "We fully back Nicola Sturgeon as she negotiates with the European Union to take the mandate we were given at the referendum on Thursday to keep Scotland in the European Union.
"We will leave no stone unturned to look at what that can look like."
Mr Murray said Labour would not support further moves towards Scottish independence.
"Our manifesto was quite clear that we can't support a second referendum.
"That position hasn't changed but we're leaving all options open at this stage and I don't think it's in anybody's gift, anybody's power at this stage, to come to a determination on what's right and what's wrong.
"We're going through a constitutional upheaval that nobody quite knows where it will go.
"I think we need to pause and I think we need to reflect."
Mr Murray has published his letter to the Labour leader.