Rarely has a sitting British prime minister seemed so powerful. Two weeks after triggering Article 50, Theresa May rides high in the polls – higher perhaps than any serving prime minister since Margaret Thatcher in 1987, at the pinnacle of her power.

On paper, May’s parliamentary majority might seem slender. But as a Brexit government, the current administration enjoys additional support from Ulster Unionists and elsewhere, giving May and her ministers a working majority of 40 plus.

What about those backbench Tory rebels we have spent so much of the past two decades hearing about? Might they hold May hostage? No. The Eurosceptic rebellion – that great Tory Euroschism – is over. Trust me on this: I used to be one of them.

If the Tories are now polling consistently at about 40% in the polls – enough to win them a 100-plus majority at the next election – what about the other 60% of the country? Currently, the non-Tory tilting 60% are represented by a combination of Jeremy Corbyn, Tim Farron or Nigel Farage. You only need to say this to see the problem: Britain currently has no credible opposition.

Why? What has gone wrong?

Anyone angry about an absence of opposition needs to wake up to the fact that politics has become a cartel. It has been rigged by established parties in Westminster. What was once a stodgy Lab-Con duopoly has morphed, by default, into a Tory monopoly.

Central bankers set interest rates and decide economic policy. In Britain and much of the wider west, a myriad of “experts” makes public policy with little reference to the public.

More and more voters recognise this, which is one of the reasons why voters are turning to anti-establishment parties – not just in Britain, but across Europe and in the US. Yet too many on the left do not seem to get any of this. They insist on seeing the rise of the new radicals as an expression of angry nativism, of xenophobia and intolerance. It isn’t. The ire of political insurgents is aimed at the incompetence of the elites – not at outsiders. The failure of officialdom to control the borders is, in the eyes of many voters, merely one manifestation of their ineptitude.

Far from strengthening traditional centre-left parties, the mood of insurgency that animates the electorate has weakened them. See Ed Miliband or Hilary Clinton for details.

What does the left need to do to change this? A good place to start would be to ask why so many of the left seem to side with the likes of Goldman Sachs. During the recent EU referendum, why were so many on the left on the same side as big banks and Brussels lobbyists? How come the party founded by Keir Hardie has ended up on the same side as unelected Eurocrats?

A powerful oligarchy is emerging in Britain, Europe and the US. The economy is increasingly rigged for the few. Monetary policy transfers wealth from ordinary people to bankers. Inequality is rising not so much because of income differences, but because of rising asset prices. Those with hedgefunds – or houses – grow rich. The left doesn’t seem to see it.

A class of corporate super-wealthy run FTSE 100 firms. Like those that once ran the East India Company, these corporate chieftains enrich themselves at shareholder, supplier and customer expense. Yet where is the left’s critique of this kleptocratic corporatism today? Too many Labour MPs once worked as lobbyists to stand up to the various vested interests.

Capitalism is in crisis: not because the free market doesn’t work, but because the free market is no longer used to allocate capital – it’s done by the fiat of central bankers instead. Yet for too many on the left, central bankers are yet another set of “experts” to whom we should defer. Perhaps the rise of the new radicals marks the moment that the demos stop deferring?

Across the world, political insurgents have harnessed social media. Yet the UK Labour party’s main digital innovation has been to create a category of online membership that corrals half a million true believers into electoral irrelevance.

It was Vote Leave that created a “pop-up party” in parts of the country where conventional party structures have barely existed for a generation. It is David Cameron’s former staffer, Steve Hilton, who co-founded Crowdpac, an online platform that allows independent candidates to raise funds and do politics free from vested interests.

Opposition to the emerging oligarchy is coming. It’s just not coming from the established left.