The UK Government wants to "hem in" new tax responsibilities being devolved to Holyrood, according to Finance Secretary John Swinney.

Westminster and the Scottish Government have set out different proposals for adjusting the amount of cash given to Scotland as a result of control over landfill tax and stamp duty passing to the Scottish Parliament under the Scotland Act 2012.

The UK Government is arguing for a one-off adjustment to the block grant - Scotland's funding allocation - as well as a change to the ratios used to calculate the Barnett formula, which is the method used to work out the funding share.

The Treasury also proposes that any adjustment to the block grant should include constraints to ensure there is no cumulative gain or loss to the Scottish budget over the period to 2030.

The Scottish Government says Westminster's position differs from the one-off adjustment previously agreed by the two administrations, which was the basis on which the legislation was passed by the Scottish Parliament.

MSPs on Holyrood's Finance Committee have raised concerns about the progress of negotiations ahead of the draft Scottish budget this autumn.

Mr Swinney told the committee: "I feel a very strong obligation to the basis on which Parliament gave its support to the Scotland Act and I think we're shifting more and more away from that basis."

Asked for his views on the motivation behind the UK Government position, he said: "I don't quite understand what the rationale is because if the rationale is to increase the accountability and responsibility of the Scottish Parliament for the decisions that it takes, which was a purpose of the Scotland Act 2012, I see that as being undermined by both the Barnett abatement mechanism and the constraint factor, because it is essentially constraining what we can actually do.

"It is not actually saying to the Scottish Parliament: 'Here are a couple of tax responsibilities, you go off and you do them and you take the risks and the rewards for this'. It is all getting put into this very contrived analysis and that to me contradicts the purpose of the Scotland Act.

"I think that's probably the reason why they're doing it, I think there's a sense that the UK Government, having given out these responsibilities, wants to kind of hem them in at the same time."

Mr Swinney said he met with Chief Secretary to the Treasury Danny Alexander last week to discuss the issue and another meeting is forthcoming.

But he acknowledged time is running out for an agreement, adding: "There is a point at which the discussions stop and that is that I have to set the budget and I have to inform Parliament what I expect to be the tax take from the devolved taxes.

"It also needs to have the block grant adjustment number to make the budget complete and that process has to be completed by October 9.

"In terms of the point that I would require to know what is the size of the block grant adjustment, I think no later than the last week in September is the absolute back stop that I could finalise a budget with an agreed block grant adjustment number on it."