Anas Sarwar will attempt to get his Scottish Labour leadership campaign back on track today by committing the party to supporting the union.
Mr Sarwar will state that Labour under his stewardship will never back independence.
The Glasgow MSP, who has faced a backlash for sending his children to private school and being involved with a company that does not recognise trades union rights, will send a message to party voters that he has the credentials to secure their backing.
On the third anniversary of the independence referendum, Mr Sarwar will state that Labour lost voters who questioned the party’s commitment to Scotland’s place in the UK.
He said Labour fought against independence in 2014 “because of our Labour values, not despite of our Labour values”.
Mr Sarwar – who led the party’s distinct campaign United With Labour – said: “Three years on from the SNP’s referendum defeat, the divisions in Scottish society have not healed.
“I was proud to campaign to keep Scotland in the UK in 2014, travelling the country in the ‘United With Labour’ bus to speak to thousands of voters, and writing Labour’s red paper on our vision of solidarity, equality and social justice.
“As a socialist I will never apologise for opposing nationalism, and the Labour Party should never apologise. We fought for Scotland’s place in the UK because of our Labour values, not despite of our Labour values.
“I thank every single Labour member and supporter who campaigned in that referendum, often in the face of hostility from nationalists. Now that we know the scale of the cuts an independent Scotland would have to make, you saved public services and you prevented even deeper austerity.”
He added: “The threat of a second independence referendum has been lifted after voters sent a clear message to Nicola Sturgeon in the recent General Election, allowing the Scottish Parliament to finally debate issues such as education, the NHS and fairer taxation. That is what I will relentlessly focus on during the course of this leadership campaign.
“But as a party we must accept that some voters turned away from us because they didn’t trust us to protect Scotland’s place in the UK.
“That’s why, under my leadership, voters will know that our support for Scotland’s place in the UK will never be in doubt.”