THE prospect of a second independence referendum should Scotland be dragged out of the European Union against its wishes has been brushed aside by UK cabinet minister and leading Leave campaigner Chris Grayling, who dismissed it as “just talk”.

He insisted the country would vote as “one United Kingdom” and that the result should stand on that basis with no need for a repeat of the 2014 poll.

The intervention by the Commons Leader came as there were more “blue on blue” attacks as Tory Brexiteers insisted a vote to leave would enable the UK Government to scrap VAT on fuel to help Britain’s poorest households but Tory Remainers branded the assertion “fantasy land” economics.

And pro-Remain Business Secretary Sajid Javid attacked his former pro-Leave cabinet colleague Iain Duncan Smith – who accused him of privately backing a divorce from Brussels – for playing "the man rather than the ball". Mr Javid has denied Mr Duncan Smith’s claim.

After making a speech that warned of the risks of remaining in the EU, Mr Grayling was asked that, if the UK voted for Brexit on June 23 but Scotland voted for Remain, would not that lead to a second Scottish poll and the possible break-up of Britain.

He replied: “It’s not remotely either sensible or feasible for Scotland to start talking about a second referendum…The people of Scotland voted very clearly to stay in the Union and Alex Salmond said at the time that was a decision for a generation; we should hold him to that.”

The Conservative frontbencher stressed how, if Scotland had voted Yes to independence in 2014, then the nation would now be in “deep financial trouble” given the collapse in the oil price; the choice facing an independent Scotland would have been between massive tax increases or huge spending cuts, argued Mr Grayling.

He added: “It’s worth saying in the recent Scottish elections, the SNP lost their majority in the Scottish Parliament. Talk of a second referendum is just that. We are one United Kingdom. The people of Scotland voted for one United Kingdom and to be part of that. What we vote for on June 23 as one United Kingdom is what we should stand by.”

In an article in The Sun, senior Tories Michael Gove and Boris Johnson and Labour's Gisela Stuart stressed how the tax on energy bills could not be scrapped because of EU rules.

They wrote: "The least wealthy are hit particularly hard. The poorest households spend three times more of their income on household energy bills than the richest households spend. As long as we are in the EU, we are not allowed to cut this tax.”

They added: “When we Vote Leave, we will be able to scrap this unfair and damaging tax. It isn't right that unelected bureaucrats in Brussels impose taxes on the poorest and elected British politicians can do nothing."

But George Osborne dismissed Vote Leave’s claim as “fantasy land” economics, stressing how Brexit would lead to a smaller economy, "a hole in public finances" and higher taxes, including VAT.

The Remain camp also released a report, which they claimed detailed Leave's "unaffordable" spending commitments, which totalled £110 billion and which eclipsed the potential saving from leaving the EU.

But Vote Leave hit back with Matthew Elliott, its chief executive, saying: "Britain Stronger In Europe are simply making up numbers and have invented pledges that don’t exist. If we Vote Leave, we can spend the £50m we hand to the EU every day on our priorities like using a small proportion of it to cut energy bills and easing the pressure on family budgets.

"The Remain campaign should admit that if we vote In, then Brussels will be in charge of VAT levels and will continue taxing low-income families," he added.

In his speech, Mr Grayling insisted that the Eurozone was on the road to ever closer union and that if Britain stayed in the EU, it would have no opt out from many economic and social measures.

“So when there are new rules on pensions, skills and health, they will apply to us too. It means the EU starting to set rules for our NHS; with no opt-out. And millions more people[will be] able to access our free-at-the-point-of-delivery services as countries like Albania, Serbia and then Turkey join the EU.”

The Commons Leader argued that once deeper integration occurred, then Britain’s influence would diminish as would its sovereignty.

“There will be no reformed European Union British-style. Instead we will be subject to most of the integration that the Eurozone is poised to embark upon whether we like it or not. We will have little say in what they decide is necessary to pursue their goal of political union…That is not for us.”

Meantime in Birmingham, Mr Javid warned that small businesses would be "hit hard" if the UK voted to leave the EU.

The Secretary of State said it was a "dangerous" misconception to believe that smaller firms would be unaffected by Brexit.

He cited analysis by the Department for Business, estimating that eight per cent of small businesses exported to the EU and a further 15 per cent were in the supply chains of other firms that did so.

Britain Stronger In Europe calculated that that amounted to around 1.2m businesses.

“Make no mistake, if we vote to leave the EU, small businesses will be hit hard,” declared Mr Javid.

"You may have heard the myth that only massive multinationals want us to stay in the EU; that small businesses want out; that hardly any small firm exports to the EU, so leaving it won't be such a big deal.

"That's just plain wrong. It's a misconception that could have dangerous consequences for millions of people who rely on small businesses for their jobs and for their livelihoods," he added.

Asked about Mr Duncan Smith’s claim that the Business Secretary privately backed an Out vote despite of his public support for In, Mr Javid said: “What that shows is unfortunately some people in this debate prefer to play the man rather than the ball. Which tells you all, really."

The cabinet minister, asked if he had changed his mind on the issue, replied: "My view has always been clear on the economic issue. I'm the first to admit…the EU is not perfect but there's lots of it that works.

"What is absolutely clear is that when faced with this question of staying in or leaving we are much stronger In. Our economy is much stronger In, whether small companies or large companies," he added.