The SNP have demanded that Scottish MPs are not barred from a controversial vote on building a third runway at Heathrow.

Earlier this week Conservative ministers suggested that Scotland’s 59 MPs could be excluded and the issue branded ‘England-only’.

Outraged Scottish, Welsh and Northern Irish politicians hit back warning that the future of the UK's hub airport affects the economy right across Britain.

The row erupted just a day after the Conservatives pushed through plans to restrict the voting rights of non-English MPs, 'English votes for English laws’.

Under the policy English MPs will have to give their backing to any Bill judged ‘England-only’.

The SNP, Labour and other opposition parties warn the move will endanger the Union and create ‘second class” MPs.

First Minister Nicola Sturgeon even claimed yesterday David Cameron's government was doing a "good job" for the SNP with Evel .

The policy would drive up support for Scottish independence, she predicted.

On Thursday the Leader of the House Chris Grayling said in a radio interview that a Heathrow vote could be deemed 'England-only'.

Mr Grayling said that votes on flight slots or airspace capacity would be done "on a UK-wide basis".

But, he said, if the vote on Heathrow was about a planning application, an issue which is devolved in Scotland, "it might be very different".

Under Evel issues judged 'England-only' will include those over which the Scottish Parliament has control.

Ministers argue that English politicians do not get a vote on those matters north of the border.

Mr Grayling has said that he believes Evel will bring fairness to the devolution settlement which in turn will help secure the future of the Union.

But the SNP accused ministers of playing politics with the issue and deliberately expanding the definition of 'England-only' to include issues which have a direct impact on the rest of the UK.

Drew Hendry, the SNP’s Westminster transport spokesman, said: “Expansion of airport capacity impacts on connectivity for the whole of the UK and, therefore, any vote must be an issue on which all MPs have a say.

"Indeed, the Scottish Government have called for guarantees to be attached to new capacity which secure minimum levels of access between Scotland and London.

“That move is essential not only to help our economy and businesses connect to global markets, but will also ensure that the significant numbers of inbound business passengers and tourists travelling through London airports to Scotland continue to have that option."

The Tories are divided over the future of Heathrow.

A number of Tory MPs represent seats that would be directly affected by noise and pollution if a third runway was given the go ahead.

Among the high-profile Conservative MPs fighting Heathrow expansion is the current London mayor Boris Johnson.

Mr Hendry said: "The Tories' EVEL plans seem to have less to do with what is in the national interest and everything to do with the festering tensions on the Tory backbenches.

“The expansion of airport capacity has constantly been promoted by the UK government as a national infrastructure project – with huge ramifications on air connectivity for Scotland, Wales, Northern Ireland and the regions of England and it will have massive impact on travel, exports, growth and jobs across the four nations of these islands – not just London and the South East of England.’’

Earlier Ms Sturgeon used the micro-blogging site Twitter to tell the Conservatives: "Whoever advises Tories on Scotland is doing good job - for @thesnp."

Under Evel the Speaker of the Commons will be required to judge if a Bill is ‘England only’ or ‘England and Wales only’.

English MPs have been told that they will not have to accept laws they did not back.

But Scottish MPs could still also have the ability, alongside others, to veto Bills at a later stage, as all 650 MPs will get a final vote on any legislation.