Yesterday's publication of the Westminster Coalition's Scotland Bill is the next stage in a "flawed process", say Scotland's Greens.
They say the decision-making has been dominated by the interests of the big political parties, rather than of Scotland's people.
Alex Salmond, the country's First Minister, and leader of the Scottish National Party (SNP) has also accused Treasury officials of using an overhaul of devolution as a smokescreen for cutting Scottish spending.
"It's a clever fiddle", one trade union observer told Ekklesia, as the Bill was unveiled on St Andrew's Day, Scotland's national day.
At a press conference in Edinburgh, Mr Salmond produced figures suggesting the total cuts in the block grant would be £8 billion more than the money raised in income tax if the powers had been in place over the past decade.
He also claimed that most of the extra income tax revenues generated by future economic booms would flow to the Treasury, not Scotland.
Meanwhile, the Greens challenged other parties to set out how they would use the powers in the Bill to ensure that Scottish politics is not dragged toward the Con-LibDem Coalition's right-wing agenda, and instead to help create a more equal society.
Patrick Harvie MSP commented: "The Calman process, like the National Conversation, was a one-sided discussion with important options closed down and the public excluded. Both failed to live up to the participative ideals which the Scottish Constitutional Convention embodied."
He continued: "As a result, the new powers being proposed for Holyrood are not well designed to help us build a fairer and more sustainable Scotland. But however flawed these proposals are, each of Scotland's political parties should now say how they would use them, and how their vision for Scotland differs from the Westminster consensus."
"In particular," claimed Mr Harvie, "every party apart from the Greens is currently set to hand on Tory cuts instead of raising revenue. The Scotland Bill published today would give Holyrood more flexibility to vary income tax fairly. For too long, the electorate have been told that they can have European style public services but pay US levels of tax. This lie can no longer be tolerated."
"Greens will never accept the Tory cuts agenda, and will instead find the most progressive way to fund Scotland's vital public services. We will do this during this year's budget, during next year's election, and whether with the Calman powers ,or in an independent Scotland, we will continue to do so," he concluded.
But the SNP deny that they are tools of the Conservatives, saying they will vote against the Bill unless there are changes, as well as demanding full taxation powers to be transferred to Holyrood.
“The current Bill gives Treasury civil servants an excuse to do what they always wanted to do, which is squeeze the Barnett formula. It’s a backdoor way of squeezing Scottish spending,” said Alex Salmond.
Meanwhile, the Labour, Liberal Democrat and Tory leaders in Scotland issued a joint statement supporting the Coalition's legislation.
The tax powers are set out in Recommendation 3.1 on p111 of the final Calman report: http://is.gd/hZfED