I clearly remember pondering, on 24 June 2016, why there was not more public and political outrage at the idea of a British government putting itself above the law, and using the royal prerogative to execute the referendum result. I find myself in exactly the same mindset in terms of the potential undermining of our democracy, government and sovereignty by a hostile foreign power – Russia – in what appears to be a secretive coup.

As a transparency campaigner and a passionate believer in our British values, as well as political and democratic systems, I am worried. People were told that walking out of the EU would liberate us from the clutches of unaccountable bureaucrats and would allow us to “take back control”. Auberon Waugh’s “junta of Belgian ticket inspectors” would be sent packing, the British people would reclaim sovereignty and British courts would decide British law for British people. The fog of bureaucracy would be blown away by the accountability and transparency that we supposedly enjoyed in the days before 1973.

It is turning out very differently. Think of Brexit as a matryoshka, or a Russian nesting doll, with voting to leave the EU as the outer doll, representing all the various things we were sold: free trade, prosperity, sovereignty, transparency, increased control over borders, and less money sent to Brussels. Pulling off the outer doll reveals another doll that represents something much more worrying.

Over the last two months, on an almost weekly basis, we have heard allegations of unidentified sources of money being used in the leave campaigns, which may have circumvented rules designed to uphold the integrity of our democratic process, which said campaigns purported to want to reclaim. The mysterious Constitutional Research Council (CRC) is reported to have routed £425,000 into pro-Brexit ads in London via the Democratic Unionist party. Conveniently, Northern Irish political donations are treated as confidential, a legacy from the Troubles. The same CRC gave the Tory MP Steve Baker £6,500 in 2016. At the time Baker was chairman of a Tory hard-Brexit caucus, the European Research Group (ERG), which was behind the sinister Boris Johnson and Michael Gove letter exposed by the Mail on Sunday. And what is Baker doing now? He is junior minister in the Department for Exiting the European Union (DExEU).

The Electoral Commission is investigating the funding of Leave.eu and its largest donor, Arron Banks. These allegations focus on whether donations were permissible and on whether Banks or his company acted as an agent for other donors. Banks denies all the allegations against him. Meanwhile, Vote Leave, the official campaign to quit the EU, last week also came under investigation for potentially breaching the rules by giving £625,000 to a 23-year-old fashion student in connection with his campaign to get young voters to back leave.

The third doll in the matryoshka, fittingly, is Russian. All 17 of the US intelligence agencies agree that the Kremlin interfered in the US presidential election – the only debate is to what extent the Trump campaign colluded. Now it seems that Russia weighed in on the Brexit referendum for exactly the same reasons: to divide the west by breaking up Nato and the EU – and excluding the effective and influential US and UK from continental European affairs as far as possible. We now know that thousands of Russian bots were active in pushing the Brexit message on social media, as were workers in the St Petersburg “troll factory”.

The big question now is to what extent Russian money came into the leave campaigns, and is in effect funding a cold war. How deep does foreign interference from a hostile power go in undermining our democratic systems? When leave campaigners try to write off the foreign interference as a ploy by remainers, they fall into a trap set by the Russians, which is to set us against each other. In all of this, we should remember that we are all British citizens and even if we voted on different sides in June 2016, we all value our democracy and fear foreign corruption of our way of life and country. That means standing firm against foreign powers that wish to see our institutions undermined.

Which brings me to the innermost doll: illiberalism. Of the 52% who cast their vote for leave, how many were voting for Britain to become a deregulated, super-low-tax, small-state country? The Vote Leave bus message that told voters “We send the EU £350m a week. Let’s fund our NHS instead” has been widely discredited. But what if the people who have grabbed the Brexit steering wheel were hostile to the very idea of the NHS?

Gove and Johnson are pushing for hard deregulation under the cover of hard Brexit. With the ERG and the highly influential Legatum Institute on their side, the duo have demanded that the prime minister drop taxes and make a bonfire of the regulations that protect us. As Marie Antoinette said of the poor, “let them eat cake” – the modern equivalent being “let them eat chlorinated chicken”. The extremely successful vacuum-cleaner magnate James Dyson has been more open than Johnson and Gove in describing the post-Brexit country he wants: one that sees an end to corporation tax, and a slashing of protection for workers’ rights. In the secret “bullying” Gove and Johnson letter, for Theresa May’s eyes only, they talked about circumventing normal cabinet protocols, getting rid of moderate ministers and parachuting in a Brexit “implementation taskforce” to overrule Whitehall and our civil service.

There is every likelihood that this taskforce would involve Matthew Elliott, the lead Vote Leave campaigner who now works for the Legatum Institute, as well as other Legatum staff, none of them elected by anyone, or loyal to anything other than their employer. The Legatum Institute is a handsomely funded extreme free-market thinktank fuelled by offshore cash from the Caribbean and Dubai. Behind it stand the Chandler brothers, who made their billions in Russia’s most turbulent years, and once owned 4% of Gazprom.

DExEU, of all ministries, has not responded to multiple freedom of information requests about its relationship with Legatum. The Mail on Sunday now has photographic evidence of Shanker Singham, director of economic policy at Legatum, and Gove at a behind-closed-doors Commons seminar on Brexit last Friday, which was also attended by No 10 and officials from the US embassy.

The things being smuggled in under the cover of Brexit will damage so much of what we hold dear. A cabal of tycoons would see their wealth and influence turbocharged, while the mass of the population would see their prosperity, their security and, ultimately, their liberty dwindle away. And this is the dark nature of the inner doll: the end of the western model of capitalism married to liberal democracy. The turbulence caused by crashing out of the EU would just be another opportunity for these individuals.

The matryoshka dolls have only started to come apart and reveal the inner truths in the last six weeks. But this is just the beginning, not the end, of the process. The more people glimpse the inner doll, the more I am convinced that an overwhelming majority of the electorate – irrespective of how they voted in the referendum – will understand the deception that is being perpetrated. They will demand that our democracy be defended.

• Gina Miller was the lead claimant in the successful legal fight to allow parliament to vote on whether the UK could start the process of leaving the EU