DAVID Cameron has made clear his determination to press ahead with banning Scottish MPs from voting on parts of the British Budget as he was warned not to let his enthusiasm for English Votes for English Laws (Evel) undermine the fiscal integrity of the United Kingdom.

During his trip to Edinburgh, the Prime Minister echoed Chancellor George Osborne, who, earlier this week, caused controversy by insisting Evel would "have to apply on areas connected with the Budget" given that power over tax bands and rates on earned income in Scotland were going to be devolved to Holyrood.

Mr Cameron declared: "It wouldn't be appropriate for English constituents to have a rate of tax essentially imposed on them by Scottish MPs.

"So we're going to have to find a way through the Evel proposal to safeguard the integrity of the UK budgeting process but also to make sure that there's a fair arrangement."

He also decried First Minister Nicola Sturgeon's pronouncement that, after the General Election, SNP MPs would vote on matters affecting the English NHS, describing it as "a very big change", which was hard to explain.

He accepted overall spending decisions had, through the Barnett Formula, consequences for Scotland, but stressed it was wrong to "argue MPs from Scotland should be able to vote on the minutiae of health and education in England".

The issue of banning Scottish MPs from parts of the Budget was raised at Westminster when David Mundell, the Scotland Office Minister, made a Commons statement on the draft clauses setting out the proposed new powers for Holyrood.

Alistair Darling, the former Labour Chancellor who headed the Better Together campaign, pointed to the Smith Commission recommendation that all MPs should decide the Budget, stressing it was "entirely inconsistent" with the views of Mr Cameron and Mr Osborne.

He asked Mr Mundell: "Does the Minister accept that any future reforms will have to be fair but must not undermine the fiscal integrity of the United Kingdom? If they did so, we would end up with all the restrictions we see in the eurozone, which no one in this country, north or south of the border, wants."

The Minister did not defend the proposal to ban Scottish MPs from parts of the Budget, saying only the Chancellor had made clear "as we move forward with the different settlement in Scotland, there will be elements of the Budget that do not apply to Scotland".