One of the Government's most senior officials has made the incendiary suggestion that Britain does not need its own farming industry.

In leaked emails obtained by The Mail on Sunday, powerful Treasury adviser Tim Leunig argues that the food sector is not 'critically important' to the economy – and that agriculture and fishery production 'certainly isn't'.

In his astonishing remarks – which comes as the UK prepares to enter crunch post-Brexit trade talks with Donald Trump – Dr Leunig implies that the UK could follow the example of Singapore 'which is rich without having its own agricultural sector'.

Dr Leunig is a long-standing colleague of Boris Johnson's No 10 enforcer Dominic Cummings, and his intervention exemplifies the radical thinking within Boris Johnson's inner circle against bastions of the Establishment such as the Civil Service and the BBC.

Powerful Treasury adviser Tim Leunig argues that the food sector is not 'critically important' to the economy

Those tensions at the top of Government spilled over in astonishing public fashion yesterday when Sir Philip Rutnam, the top civil servant in the Home Office, resigned following a clash with Priti Patel, citing a 'vicious and orchestrated' campaign against him.

In response, No 10 sources branded Sir Philip 'Sir Calamity' and 'a poster boy for failure'.

Britain? It could be like Singapore! Controversial aide claims we could import EVERYTHING that we eat

A senior economic adviser to new Chancellor Rishi Sunak has argued that Britain could become 'like Singapore' and import all our food.

Dr Tim Leunig – a powerful voice in Whitehall – claims that the agriculture and fishing industries make a negligible contribution to the economy, and points out that the former British outpost 'is rich without having its own agricultural sector'.

In his controversial comments, he also suggests farmers should not be given tax breaks denied to other industries.

Dr Leunig's astonishing comments come as the UK prepares to enter vital post-Brexit trade talks with both the EU and the US, where negotiators would be expected to fight for British farmers. Already the industry has urged the Government not to lower standards to allow cheap, sub-standard products such as chlorinated chicken to flood the UK market and put British suppliers out of business.

Dr Tim Leunig – a powerful voice in Whitehall – claims that the agriculture and fishing industries make a negligible contribution to the economy

Last night, a bullish Boris Johnson said: 'We have the best negotiators in the business.' And he vowed to 'drive a hard bargain' with President Donald Trump which would trade 'Scottish smoked salmon for Stetson hats'.

Dr Leunig, an associate professor at the London School of Economics, who also holds advisory positions in the Education and Environment Departments, made his arguments in emails sent last week to the National Food Strategy, the Government's wholesale review of the British food system.

He wrote: 'Food sector isn't critically important to the UK, and ag[riculture] and fish production certainly isn't'. He pointed to figures suggesting that it adds just 0.5 per cent in extra value to the economy.

Dr Leunig then questioned the special tax breaks given to farmers, saying: 'We know that supermarkets also make very little, and that lots of restaurants go bust.

'Not sure I buy a 'life is tough for farmers, easy for restaurateurs' approach.'

When he was challenged by fellow members of the review's advisory panel, he responded: 'All I am saying is that, as a logical possibility, a nation (or region) can import stuff. We see that in many places for many goods and services. Singapore imports (almost) all its food, Germany all its oil, Japan all its planes and all its oil, Australia and New Zealand import all their cars, all their planes and all their oil, while Iceland imports oil, cars, planes and graduate-level education.'

Last night, a senior industry insider said: 'The UK is a fantastic place to produce food and we have some of the highest standards in the world. In a trade deal with the US, we face the prospect of imports of food produced to standards that would be illegal for our own farmers to employ. Why would any adviser to Government seek to decimate our own farming sector?

'Surely the first duties of any Government should be to defend and feed its people. It seems to me that a country that cannot feed itself is no country at all.'

But a Government spokesman said that Dr Leunig's comments were 'not Government policy'.

International Trade Secretary Liz Truss will tomorrow announce the UK's negotiating objectives for a transatlantic trade deal, and is set to say it must 'uphold our high standards on food safety and animal welfare' as well as protect the NHS.

The National Farmers' Union has been pressing the Government not to relax standards, saying it would be 'morally bankrupt' to allow chemically cleaned poultry, hormone-treated beef and genetically modified fruit and vegetables.

The union said it would be 'insane' to sign a trade deal on that basis.

How senior economic adviser Dr Tim Leunig is a brainbox with wheezes on everything from third class carriages to paddling pools

Tim Leuing most controversial policy idea – until today – was to pull all Government support from 'failed' Northern cities and encourage the inhabitants to migrate South.

'Barmy,' said a furious David Cameron, who was Tory leader when Dr Leunig floated it in a think-tank report in 2008. 'Rubbish from start to finish.'

Mr Cameron added: 'I hear he is off to Australia. The sooner he gets on the ship, the better.'

But Dr Leunig was not planning to emigrate – and four years later he sailed into the heart of Mr Cameron's Government as an adviser to Michael Gove.

He now holds an unusually powerful position in Whitehall, with footholds in the departments of Education, the Environment and the Treasury, where he became economic adviser to the Chancellor just weeks after Boris Johnson became Prime Minister last summer.

Previously, Tim Leuing's most controversial policy idea was to pull all Government support from 'failed' Northern cities and encourage the inhabitants to migrate South

Mr Gove was halfway through his radical tenure as Education Secretary, waging war against the teaching establishment, when Dr Leunig joined his team alongside Dominic Cummings – Mr Gove's most senior adviser.

Mr Cummings now performs the same de facto chief of staff role for Mr Johnson, and has extended his ideological battleground to include large swathes of the public sector and other 'vested interests'.

Dr Leunig, 49, shares with Mr Cummings a desire for radical thinking and an apparent indifference to the objections of opponents. After attending a Kent grammar school and obtaining a First in modern history and economics at Oxford, Dr Leunig joined the London School of Economics, where he immediately started making waves with his radical brand of economic thinking.

The associate professor, a keen gardener who is married to Julia Cerutti, an Oxford contemporary and Government actuary, says that many of his ideas are inspired by frustrations in his own daily life – such as when he called for third-class, standing-only carriages on trains, for a flat fare of £1, to ease the overcrowding he experienced during his commute from Richmond in South-West London.

And when he was prevented by a hosepipe ban from filling his daughter's paddling pool, he embarked on an analysis of the water industry which led him to decide that the bans were a 'crude prohibition' which had a disproportionate impact on users. He concluded that if the water companies were given an incentive to be less wasteful, the water saved could be sold to others at a higher price, allowing him to pay extra to fill his paddling pools if he so wished.

Michael Gove was halfway through his radical tenure as Education Secretary, when Dr Leunig joined his team alongside Dominic Cummings – Mr Gove's most senior adviser

While he was working in Mr Gove's department, as an adviser to Liberal Democrat Schools Minister David Laws, Dr Leunig also argued that more needed to be done to tackle the under-achievement of the 'dominant racial group' – white – in schools.

He told a headteachers' conference: 'If your school happens to have a lot of Chinese students you are likely to do well – that is the reality. It is being white that is the problem in schools at the moment.'

His remarks coincided with the leak of a paper written by Mr Cummings, which said inherited intelligence was more important in GSCE test results than school performance.

Dr Leunig's outspokenness is matched by fearlessness. When Mr Gove first proposed a new, highly traditional, history curriculum for schools, Dr Leunig emailed him to say: 'You will, personally, be mocked if you go ahead with this, and rightly so.'

Mr Gove replied: 'Dear Tim, I am out of the UK right now – trying to broaden my horizons but in fact only expanding my waistline. Thank you for being so detailed and candid. The two things I value most in advice – and advisers – are evidence and honesty. Drawing up the curriculum has been a difficult political exercise.'

But it was Dr Leunig's report Cities Unlimited, for the Tory-supporting Policy Exchange think-tank, which has so far gained him the most enduring notoriety.

His argument – that instead of pouring money into declining Northern cities, the Government should direct housing and industry support to London and the South where people would prefer to be based – was seized upon by Labour, which accused the Conservatives of dismissing the North as 'worthless'.

Dr Leunig now stands accused of taking the same attitude to the entire farming industry.

But last night a friend said: 'Tim is highly intelligent. Perhaps too intelligent for his own good sometimes'.

We have taken back control and we're not going to trade it away: MICHAEL GOVE says Britain can use its recovered sovereignty to be a force for good in the world

We are living, Pope Francis has said, not so much through an era of change as a change of era – one in which expectations and opportunities have been transformed.

The financial crisis and other failures of leadership from a past generation of political and business leaders have turned people against distant and unaccountable power-brokers. Citizens want to bring de-mocracy back home.

Bringing institutions back closer to the people they are supposed to serve is a critical demand for this new age. And putting the people's priorities at the heart of a re-energised democracy means addressing inequalities and divisions.

This re-invigorated commitment to help undervalued communities and those families who have been overlooked goes hand-in-hand with a new approach to the accelerating pace of technological change.

Our aim is to secure a comprehensive free trade agreement and find common ground on issues such as our fisheries, security and aviation, says Michael Gove

Nations which are flexible and nimble are best equipped to ensure new technologies can be harnessed in a way which benefits all – not just those with connections.

These new political realities can be seen worldwide, and they are particularly powerful in Britain. They lay behind the vote to leave the EU and Boris's victory in the General Election, and mean we can now ensure the UK shapes this new era in a positive way.

And we can use our recovered sovereignty to be a force for good in the world and a fairer nation at home. We are entering a new chapter in the history of these islands.

This week, the Government will take significant steps to shape that future. We will set out our proposals for trading with the US, the world's biggest economy and our strongest ally. In Brussels tomorrow, the Prime Minister's chief negotiator, David Frost, will open talks with our EU partners about the shape of our new relationship, based on free trade and friendly co-operation.

Our aim is to secure a comprehensive free trade agreement and find common ground on issues such as our fisheries, security and aviation. I believe we can secure a great new deal but it is vital we are clear from the start that these talks are taking place in new times.

Yes, we want the best possible trading relationship with the EU. But we will not trade away our newly recovered sovereignty.

The UK's approach to the future relationship was clearly set out by the Prime Minister during the Election campaign and again in his Greenwich speech last month.

The vote to leave the EU and Boris's victory in the General Election means we can now ensure the UK shapes a new era in a positive way, says Michael Gove

First and foremost, we see it as one based on friendly co-operation between sovereign equals. Just as we respect the EU's sovereignty, autonomy and legal approach, so we expect them to respect ours. That means there must be no obligation for our laws to be aligned with those of the EU or its institutions, including the Court of Justice.

Rather, each side will respect the other's independence and the right to manage its own borders, immigration policy and taxes.

And we see the new relationship developing along the lines of the EU's existing relationships with other dynamic sovereign states like Canada, Japan and South Korea. Because we will be seeking simple, streamlined and well-understood arrangements, agreement can be reached quickly. This will help both sides meet the aim, set out in the Political Declaration last October, of concluding a 'zero tariffs, zero quo-tas' free trade agreement.

Independence means not only full control of our borders, but also our waters. We can manage our precious maritime resources in a better way for the environment and jobs. Access to fish in UK waters will be for us to decide – a new approach which is both greener and fairer.

Both the UK and the EU uphold desirable standards on social and environmental protections. Indeed, the UK has a proud record of exceeding EU standards and having led the way to improving global standards in a number of key areas. On workers' rights, for example, the UK offers a year of maternity leave – with the option for parents to convert this to parental leave. The EU minimum is just 14 weeks.

And on environmental standards, we were the first country in the world to introduce legally-binding greenhouse gas emission targets, in the 2008 Climate Change Act. More recently, we were the first major global economy to set a legally-binding target of net-zero emissions across the economy by 2050. Far from diluting existing protections, we wish – as our Environment Bill shows – to go further and faster than the EU in helping the natural world.

Clearly and emphatically, the British people decided the next chapter in our island story meant taking back control. This new era requires politicians to bring power home and to ensure the rules governing countries are made by those who are directly accountable to the electorate. That is the way to ensure every citizen's voice is given equal weight, and which allows us to adapt most nimbly and flexibly to technological change. That is what we are delivering in ways that will benefit the whole of the UK.

In coming months, as the British chair of the joint UK/EU committee overseeing the Withdrawal Agreement, I will be making sure we continue to seek the best possible relationship with our friends and allies in Europe. But we would be neglecting our duty to the British people if we did not always put their welfare first. Because that remains the most important deal of all.

MAIL ON SUNDAY COMMENT: Britain doesn’t need farms? Find another box to think outside!

The Mail on Sunday is emphatically not against original thinking in government. The permanent Civil Service is far from being the fount of all wisdom. Boris Johnson’s adviser Dominic Cummings has a case when he encourages the recruitment of outsiders and troublemakers to the government machine.

So, unlike many in the media, we do not automatically deride these dissidents. Even where their ideas are self-evidently impossible, they can stimulate new thinking where it is most needed. But let us not get carried away. There are still limits.

And Treasury adviser Tim Leunig’s airy dismissal of the importance of farming, which we reveal today, goes beyond those limits. Our United Kingdom cannot be compared with the concrete-coated island of Singapore, no bigger than the Isle of Wight. Nor can it be equated with London, another densely packed city-state which imports almost every morsel that it eats.

Prime Minister Boris Johnson speaks during Prime Minister's Questions in the House of Commons

The UK is a proper country, rooted in its soil, and shaped by the distinct tastes of the food and drink it grows and makes. Most of us carry with us, however far away we travel, a picture in our minds of small fields, hedgerows, woodland and pasture, all of them distinctly and unmistakably British.

And this green demi-paradise is not the work of nature, but of farmers who have tilled and tamed and drained it over many centuries until it takes the form we now see. As for farmers, they are the embodiment of wise conservatism, the opposite of citified bohemians, governed by the seasons, aware at every minute of the virtues of hard work and of the value of experience.

One of the things we sought through Brexit was to regain the power to govern our agriculture as we wished and for our own national benefit, freed from the follies of the Common Agricultural Policy.

And it will do little good if we now instead succumb to American pressure to open our markets to the ruthless factory farming of US agriculture, with its questionable use of growth hormones and antibiotics, and its worryingly different hygiene methods. How long will our beloved countryside survive if it has to compete, unprotected, with the cheap products of that regime?

This is why it is worryingly wrong for Dr Leunig to suggest that farming is not ‘critically important’ to this country. He has mistaken cold figures for long-term truths, and ignored the emotional nature of patriotism. He should find another box to think outside.

Civil servants are not paid to decide

THE trouble with the great TV comedy Yes, Minister was that it was all absolutely true. Senior civil servants can and do frustrate the wills of politicians, whom they often regard as unqualified amateurs. They have many subtle and effective ways of doing so.

Reforming governments of both parties have tried to fight this in many ways since the 1960s, mainly by introducing increasing numbers of ‘special advisers’, who can counter the immense weight of Whitehall’s institutions.

But sometimes there are direct clashes, and the more radical the politician, the more likely these are. It is not for us to comment on the detailed relationship between the Home Secretary and her Permanent Secretary, Sir Philip Rutnam, who resigned so spectacularly yesterday.

But this general point should never be forgotten. Priti Patel is part of an elected Government with a large parliamentary majority and a solid popular mandate. She decides. Civil servants only advise. The undoubted influence of permanent officials can only be exercised if they recognise, at all times, this ultimate truth about power.