RICHARD Leonard has announced Scottish Labour will undertake a swift review into its election rout that will include developing a “clear, constitutional offer” to the nation.

While it is unclear as to what this would be, the development came as senior colleagues openly questioned the party’s opposition to a second independence referendum in light of the SNP landslide.

The Scottish Labour leader, following a weekend meeting of the party’s executive to discuss the election result, in which Scottish Labour was again left with just a solitary MP - Ian Murray representing Edinburgh South – said it was “crucial we learn the lessons of our defeat”.

He explained: “We owe this to Scotland’s communities, workplaces and most vulnerable people, who are now facing the prospect of five years more years of Tory Government.”

A swift evidence-based review of the election campaign would begin in the coming weeks to chart a way forward and see why voters, desperate for change, no longer felt Scottish Labour was the vehicle to realise that change.

“We must develop a clear constitutional offer that wins back the confidence of voters who in this election felt that we did not offer clarity over Scotland’s future.”

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Throughout the campaign the emphasis changed on when a Corbyn Government, while opposed to independence, might facilitate another referendum from up to three years to just ruling one out next year.

Mr Leonard urged his party that in the coming weeks and months, it was more important than ever it remained united.

“Neither the status quo nor the SNP’s vision for cuts and separation offers the way forward for Scotland and we owe it to the people of Scotland to offer a clear prospectus for a transformed society and economy,” Mr Leonard added.

However, his party’s opposition to indyref2 is now being openly questioned by senior colleagues, who, while they continued to oppose Scotland breaking away from the rest of the UK, nonetheless believe a second vote on the nation’s future is justified.

Monica Lennon, Scottish Labour’s health spokeswoman, made clear while she was opposed to independence, "people in Scotland have voted in very large numbers for the SNP, including many Labour voters".

She told the Sunday Mail: "The SNP blueprint for independence is flawed and will disappoint many progressive Scots who are fed up with austerity. Nevertheless, the future of Scotland must be decided by the people of Scotland."

Former Scottish Labour MP Ged Killen, who lost the Rutherglen and Hamilton West seat to the SNP, signalled his agreement on Twitter.

He said: "I campaigned on a promise to vote against indyref2, but I lost. The SNP made massive gains on a promise to hold another referendum and, as democrats, we must accept it even if we don't like it."

His colleague, Neil Findlay MSP, argued: “We cannot deny the people of Scotland a second referendum where the majority is calling for it.”

The MSP for Lothian stressed how he believed that independence would be bad for Scotland for many reasons, noting how there would be big issues at stake such as the currency, borders, EU membership and falling oil revenues.

He added: “However, if the people accept a new prospectus for independence, so be it. That is democracy and, if it happens, Labour should offer its own prospectus for a progressive, socialist, outward-looking and egalitarian independent country.”

The Labour politicians’ comments came after Labour councillor Alison Evison, the President of the local authority group Cosla, said democracy could be strengthened "by enabling the voice of Scotland to be heard through its formal processes", adding: "That must mean a referendum on independence.”

Meanwhile, Kezia Dugdale argued opponents of independence needed to find a new argument for keeping Scotland in the UK.

The former Scottish Labour leader, who stood down as an MSP earlier this year, told No campaigners: "You're wasting precious time arguing about mandates.

“Last referendum won by persuading centre-left voters 1) EU membership only safe in UK 2) A progressive Labour gov was on the horizon 3) Currency and Economic security.

"Reasons 1 and 2 have melted away and the Yes movement have been working on 3 since 2014.

READ MORE: Nicola Sturgeon: Scotland 'can't be imprisoned within UK against its will' - Michael Gove: no indyref2 under Tories

"You need a new argument for the Union which isn't rooted in Queen and country Unionism. You need this regardless of whether referendum is next year or in a generation," she added.

Ian Blackford, the Nationalist leader at Westminster, welcomed the pro-indyref2 comments from senior Labour figures.

“The SNP have a cast-iron mandate to hold an independence referendum and the UK Government must respect that. It is welcome that senior figures within Labour are recognising that mandate.

“While we will not all agree on independence, we can surely find common ground that this decision must be in Scotland’s hands not Boris Johnson's,” added the MP for Ross, Skye and Lochaber.