LABOUR needs to “win back our heartlands,” including Scotland, Sir Keir Starmer told the party’s MPs and peers last night in the first leadership hustings.

The Shadow Brexit Secretary’s words came after Labour grandee, Lord Robertson of Port Ellen, during a Lords debate on the Queen’s Speech, claimed Boris Johnson had been gifted his landslide victory by the "incompetence and stupidity" of Jeremy Corbyn's leadership.

Sir Keir told a gathering of the Parliamentary Labour Party in the Commons: "We need to understand and to address each and every reason we lost at this election but we also need to win back Scotland, we need to win back seats in Wales, and if you draw a line from London to Bristol and look south we only have a handful seats.

"So, we have got a mountain to climb," he declared.

His rival Lisa Nandy, who represents Wigan, told the hustings: "This leadership debate is possibly the most important in our history. Now is not the time to steady the ship. If we do not change course, we will die and we will deserve to."

Fellow contender Jess Phillips insisted she did not want to be the next Leader of the Opposition, rather "the next Labour Prime Minister; I want the people here to be in government".

The Birmingham MP declared: "I have dedicated my life to trying to change the lives of others but I am sick of just shifting the dial, I want to smash it."

Ms Phillips said her priorities would be ensuring everyone had a good school place for their child, felts safe on the streets and had a home to live in.

During the Lords debate, Lord Robertson, who served as Defence Secretary under Tony Blair and is a former Nato Secretary General, said: "This government came to power last month with a mandate and a majority, gifted by the incompetence and stupidity of the Labour leadership.

"But even if the Prime Minister has power, he has serious dilemmas to face as well. Leaving aside the claim of getting Brexit done, which cannot be done in the promised timescale, he has also made a series of promises and spending commitments, which will require serious and very difficult choices to be made and to be made very soon."

Earlier, Mr Corbyn was rated “10 out of 10” as Labour leader by Rebecca Long Bailey, who has become the sixth candidate in the contest to succeed him.

The Shadow Business Secretary accepted Labour had not been not trusted on Brexit, tackling anti-Semitism or its policy platform as she acknowledged the failings that led to the party's disastrous General Election result.

But she praised Mr Corbyn's leadership and character as she gave him a perfect score.

"I thought Corbyn was one of the most honest, kind, principled politicians I've ever met," she declared.

Ms Long Bailey, 40, told ITV News: "I'd give him 10 out of 10 because I respect him and I supported him all the way through.

"What we can't ignore was that Jeremy was savaged from day one by the press...We have a role as a party to develop the image of our leader and to put them forward in the most positive way but we also have a duty to rebut criticism and attacks.

"As a party we needed to have a rebuttal unit, a clear structure in place to rebut the attacks against him," explained the Salford MP.

Last night, the six leadership candidates, who also include Keir Starmer, Emily Thornberry, Lisa Nandy, Jess Philips and Clive Lewis.

Earlier, she set out the problems which saw the party lose 59 seats at the general election.

"We weren't trusted on Brexit. We weren't trusted as a party to tackle the crisis of anti-Semitism. We weren't trusted on our policies; no matter how radical or detailed they were. They simply didn't hit the ground running," insisted Ms Long Bailey.

In a break from Mr Corbyn, she signalled she would be prepared to press the nuclear button if she became Prime Minister.

"If you have a deterrent you have to be prepared to use it," she said but stressed she was "not going to be a warmonger".

She won support from Ian Lavery, the party Chairman, who announced he would not contest the leadership, and John McDonnell, the Shadow Chancellor.

Meanwhile, Ian Murray, Labour’s only Scottish MP, announced he was standing for the deputy leadership role and left the door open to a debate around splitting Scottish Labour off from the UK party.

Asked about calls for Scottish Labour to split from the UK party, the Edinburgh South MP told ITV Representing Border: “I don’t think we should have any knee-jerk reactions to what happened on December 12.

“We are all feeling incredibly sore and, yes, there will be people that will want to look at that as an option. And maybe we should look at that as an option; leave everything on the table.

“But the important thing is here not to look internally but to look externally. And I’ve always been a principled politician. I’ve always said that I’ll be honest with people.

“And the honest thing is that the public were telling us the problems with the Labour Party; both at UK level and in Scotland,” added Mr Murray, who is due to launch his bid to succeed Tom Watson formally in Edinburgh next week.

Elsewhere, Ms Phillips, who represents Birmingham Yardley, came out firmly against a second Scottish independence referendum, telling the BBC’s Good Morning Scotland: “I cannot see a circumstance where I would think that it would be better for Scotland to leave the United Kingdom. I cannot see where that would ever be the case.”