“It’s a serious threat to British democracy from Brussels.” “Faceless EU bureaucrats threaten to impose laws without the consent of the British people.” Both these statements could succinctly, and accurately, describe the proposed transatlantic trade and investment partnership – TTIP – between the European Union and the United States. But David Cameron is not scuttling to Brussels to display his bulldog spirit as he vetoes an attack on our country’s sovereignty. Nor will you catch Ukip issuing chilling warnings about EU rule. On the contrary, the Ukip MEP Roger Helmer says: “We have no alternative but to support the deal.”

And don’t expect any front-page splashes from the Daily Mail – keen as it is to berate the EU over everything from regulations on the shape of bananas to imperial measurements – about the TTIP threat. In fact, there has been all too little media scrutiny of this menace, with the notable exception of my crusading colleague George Monbiot.

TTIP is being marketed by its champions as a de facto economic stimulus for ailing Europe, providing up to £100bn in extra growth. It is presented as a free trade agreement, but existing tariffs on either side of the Atlantic are already weak because of common membership of organisations such as the World Trade Organisation. The actual aim is to strip away obstacles to large corporations making profits – such as regulations that protect our privacy, the environment, food safety and the economy from a rapacious financial sector. And – crucially – TTIP further opens up public services to private companies motivated primarily by profit rather than people’s needs.

The key attack on democracy is an element of the treaty called investorstate dispute settlement (ISDS). If you are worried about the power of corporations over our democracy, be very afraid: ISDS in effect grants multinationals the same legal position as a nation-state itself, and allows them to sue sovereign governments in so-called arbitration tribunals on the grounds that their profits are threatened by government policies. Is this scaremongering, as TTIP supporters claim? Take Australia, which signed an investment treaty with Hong Kong in 1993. When Australia’s federal government introduced legislation to enforce plain cigarette packaging, the Asian arm of the cigarette company Philip Morris used the treaty to sue it.

The most obvious threat here is to our National Health Service, already suffering from a programme of privatisation that the British people neither asked for nor consented to. Andy Burnham, the shadow health secretary, has pledged that a future Labour government would exclude the NHS from the trade deal – which is a good start. On the other hand, the Conservative health minister, and 7th Earl Howe, Frederick Richard Penn Curzon, brazenly suggests it is an opportunity for Britain’s pharmaceutical companies – which are already being accused of ripping off the NHS. If any future governments wished to definitively break from pro-privatisation policies, they could find themselves being sued too.

The majority of people oppose privatisation: 84% believe the NHS should be run in the public sector; two-thirds say the same about railways, energy and the Royal Mail. With such a consensus against running public services for profit, no wonder TTIP’s promoters have worked in so much secrecy. As the anti-poverty charity War on Want highlights, large companies have been agitating for this sort of deal for years. Corporate chief executives set up the secretive Transatlantic Business Dialogue as long ago as 1995 to lobby against regulations deemed to impinge on the ability of multinational companies to make profits; and the Transatlantic Economic Council was set up in 2007 to champion a deregulatory free trade area. Key documents related to the negotiations are to be kept from the prying eyes of the public for 30 years.

The list of “stakeholders” invited by the European commission to help shape TTIP is a salutary warning about how far the EU, in its current form, is from serving citizens rather than profiteers. After a determined effort from the Corporate Europe Observatory, the commission was forced to release the list. Of 130 meetings on the deal, at least 119 were with big corporations or their lobbyists.

Even on its own terms – regardless of the threat to democracy – TTIP should be challenged. Claims that it will boost the economy and jobs are “vastly overblown”, according to the political scientist Dr Gabriel Siles-Brügge, of Manchester University. A report commissioned by the British government concludes that ISDS “is likely to have few or no benefits to the UK, while having meaningful economic and political costs”.

This whole episode demonstrates the duplicity of rightwing Euroscepticism. It was, after all, a Tory government that brought Britain into the European Economic Community in 1973. Thatcherism began to adopt a Eurosceptic edge only when it seemed as if Brussels carried a threat to its domestic project. As Margaret Thatcher declared in Bruges in 1988: “We have not successfully rolled back the frontiers of the state in Britain only to see them reimposed at a European level with a European superstate exercising a new dominance from Brussels.”

It was never about sovereignty. The right is more than happy to surrender British sovereignty to corporations. When Cameron vetoed an EU treaty in 2011, it was not the national interest he was safeguarding, but the City’s. Similarly, Ukip’s pretence to be the people’s army against the Brussels bureaucracy is proved to be a cynical charade.

Labour needs to challenge the whole trade treaty. Other politicians need to get their house in order too. Those hoping an independent Scotland will represent a break from Britain’s corporate-obsessed consensus will have a fight on their hands if it’s a yes on Thursday: Alex Salmond has described the deal as “especially good news” for Scotland while his deputy, Nicola Sturgeon, describes it as “a reminder of the massive opportunities that European Union membership brings”.

And if our political elite won’t budge, then it’s up to the rest of us to organise. Criticisms of the EU have been surrendered to the xenophobic right for too long: a democratic People’s Europe has to be built. But TTIP is also a reminder of the constant threat from those in power. When they steal chunks of our democracy away from us, we may find that it is far from easy to win them back.