Former Scottish Labour leader Iain Gray is to represent the party on the commission set up to agree more powers for Holyrood.
The East Lothian MSP will be joined by a Scottish Labour MP – expected to be pensions spokesman Gregg McClymont – on Lord Smith of Kelvin’s Scotland Devolution Commission.
Labour is under pressure to bring its proposed package of new powers into line with the Conservatives and Lib Dems by agreeing that Holyrood should have full control of income tax.
A draft report by the party’s own devolution commission recommended such a move, but it was later watered down after a threatened rebellion by some Westminster MPs.
Labour is the last of the parties to name their members of the commission.
The SNP will be represented by Finance Secretary John Swinney and MSP Linda Fabiani, the Conservatives by former Scottish leader Annabel Goldie and academic Professor Adam Tomkins and the Scottish Greens by co-leaders MSP Patrick Harvie and Edinburgh councillor Maggie Chapman.
The Liberal Democrats have appointed former Scottish Secretary Michael Moore and former Scottish leader Tavish Scott.
Welcoming Mr Gray’s appointment, Scottish Labour leader Johann Lamont said: “Iain will offer a fresh perspective, an eye for detail and strong Labour values which will be valuable assets to this important process.
“The people of Scotland voted for faster, better, safer change and all the parties now agree that is what they will get.
“We set out a package of proposals which we believe will strengthen the Scottish Parliament while retaining the benefits of the UK.
“We will engage in the Smith Commission constructively and positively to find a consensus, but are determined to ensure Scotland has the best of both worlds.”
Mr McClymont, MP for Cumbernauld, Kilsyth and Kirkintilloch East, played a key role on Labour’s own devolution commission.
Meanwhile, Liberal Democrat leader Willie Rennie has said new powers for the Scottish Parliament in the wake of the No vote on independence must benefit employers.
On a visit to Mitsubishi Electric air conditioning plant in Livingston, Mr Rennie said: “Job-creators like Mitsubishi are the engines driving our economy.
“It is only sensible that they stand to benefit from the new package of powers to come to Scotland as a result of the Smith process.
“I want to see radical new financial powers and to find better ways of doing business between governments and agencies across the UK.
“These are reasonable yet radical proposals from which employers like Mitsubushi would reap the rewards.”
The Lib Dem proposals for boosting the economy include assigning corporation tax revenues raised in Scotland to the Scottish Government as well as prudential borrowing powers to allow further investment in capital projects and create more jobs and growth.
The party also proposes giving the Scottish Government full responsibility for skills and training in JobCentre Plus and the Work Programme.