The Conservative's commission on devolution is "moving towards a conclusion" on the balance of tax raising and spending powers which Holyrood could be given if independence is rejected.
The Strathclyde Commission was set up to look at proposals to strengthen the devolution settlement and improve the accountability of the Scottish Parliament.
Commission members told delegates at the party's conference in Edinburgh that the constitutional debate had moved beyond the status quo, and inconsistencies between what is spent and what is raised at Holyrood should be addressed.
But Professor Adam Tomkins, a constitutional expert appointed to the commission, insisted the group was not in the business of looking at "devo-max", and called on the Scottish Government to look at its own proposals for further devolution in the event of a no vote.
The commission is considering the balance between the money Holyrood is responsible for spending compared with the money it raises itself. It is also looking at the balance of power between the Scottish Parliament and councils.
It is expected to report to Scottish leader Ruth Davidson in a matter of weeks.
"I hope and expect very much that we will see clear lines from the commission."
He added: "How can it be consistent with the principles of this party to have a Parliament that is responsible for spending for £35 billion of someone's else money, without it being responsible for making the tough decisions for how to raise that money?"
Commission member and MSP Annabel Goldie said there were "imperfections" within the current devolution structure.
"The constitutional debate has moved on beyond feeling that the status quo is an option," she said.
Ms Goldie also suggested the commission's deliberations included looking at the democratic structure of Holyrood, where an SNP majority government has "railroaded" through legislation.
Professor Tomkins said the UK Government could not "unilaterally impose" further devolution.
He said: "The SNP I am afraid will still be the Government in Scotland after the referendum.
"They need to think pretty quickly and pretty coherently about what kind of devolution package they would seek to argue for in the event of losing the referendum."
He stressed: "We are not talking about devo-max. It is a nationalist solution, not a unionist solution.
"Devo-max is a scheme of power that is a perversion of devolution, in that it is designed not to strengthen and deepen the union, but to break it."