The Sunday Herald can reveal there is internal party frustration with Johann Lamont over her failure to set up the new body.
Lamont was elected last year as the Scottish Labour leader following far-reaching party reforms.
One of her first tasks was establishing a position on the SNP's policy of holding a referendum on independence.
In March, she used her conference speech to announce the creation of a "devolution commission" to examine the Parliament's powers.
She said at the time: "I will lead Labour's commission on devolution. And on that commission I want not just Holyrood and Westminster colleagues but trades-union colleagues, and colleagues from local government."
It was anticipated the commission would take a year to complete and would back an extension of Holyrood's powers.
However, despite the passage of six months, Lamont has not yet brought forward proposals to her party's Scottish Executive Committee.
One insider said there would be a "big fight" if the trade unions and other party stakeholders did not get a say on the commission's remit or make-up.
An announcement on the body is expected imminently.
A key problem Lamont faces in the review is that two of Labour's affiliated trades unions, Unite and Unison, are sympathetic to a second question on the referendum ballot.
Lamont, by contrast, wants a straight question on independence.
This newspaper can reveal that Unite tried to table an emergency motion at the March conference on the referendum.
The motion stated: "By supporting the analysis of all the potential options available in the development of this referendum – including a defined increase of devolved powers for the Scottish Parliament without political coercion – our movement can lead on this process."
However, the motion was withdrawn after behind-the-scenes negotiations.
A compromise statement on a commission was eventually agreed.
It stated: "The commission will examine all the various options about what should be devolved to where and the options as to how that devolution should be delivered."
One senior party source said: "The two-question issue is still not resolved in the Labour Party. The party leadership are delaying it in the hope that the Scottish/UK governments agree one question."
An SNP spokesman said: "This astonishing lack of leadership by Johann Lamont confirms that Labour are content to be led by the Tories in the referendum campaign, because the reality is that right-wing Tories like Iain Duncan Smith are effectively representing Labour in the No campaign – no wonder some Labour members have formed the 'Labour for Independence' group.
''The more the anti-independence parties fail to present an alternative to independence, the more people will be inclined to vote Yes to an independent Scotland in autumn 2014."
A Scottish Labour spokesman said: "The membership and remit of the commission will be announced in the next couple of weeks with its first meeting shortly thereafter."
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