Six years ago, Wonga was forced to pay for a debt advice event in my east London constituency after being exposed as behind malicious anonymous attacks on my sanity.

At the time, my surgery was full of people in dire financial straits who had taken out payday loans to make ends meet. Wonga’s staff took to the internet to label me “mental” for wanting to cap the costs of credit. As Wonga now experiences what it is like to have debts that make you go bust, my overriding sensation is not one of satisfaction but determination, as Wonga’s demise will not lead to an end of legal loan sharking. Without further action, millions continue to find that there is too much month at the end of their money and so they are easy pickings for Britain’s legal loan sharks.

For years, politicians and commentators alike claimed the company was a necessary evil, lending to those whom banks would not serve and simply filling a gap in the market. They failed to recognise that the lending in and of itself was designed to create that market – hooking people into a spiral of debt and the need to keep borrowing from them was the way in which these legal loan sharks made their profits.

Since 2015, the cost of a short-term loan has been limited to double what you borrowed. Capping the cost of credit like this hasn’t stopped people taking out payday loans, but it has stopped the spiral that got so many into trouble – with a 50% drop in people going to debt advice charities for help in the past few years alone. Where once 400 companies offered such deals, now only 150 operate in Britain, proving that capping has pushed out the predators, not the product.

Yet six years on, many rightly still ask about those ignored by mainstream finance – and the questions still go unanswered. Back then, the government made promises to expand access to affordable credit through linking up credit unions and post offices. This week in Walthamstow, our main post office will close, its core functions stuffed into the back of a local off-licence, the chance to work with our local credit union lost. Action to address the ticking timebomb of personal debt that underpins Britain’s economy is yet another casualty in the swamp that is the parliamentary time given to Brexit.

Expecting the public to be guinea pigs for predator capitalism is no better than acting as if it cannot be tackled

Six years on, predatory behaviour hasn’t disappeared – companies have simply changed their products to evade what regulation now exists. Provident Financial, the doorstep lender, offers the Vanquis credit card, whose costs are not capped, as the 5 million Brits stuck in problem debt on credit cards know all too well. The founder of Amigo Loans was censured by the Office of Fair Trading for his previous loan offers. It asks borrowers to use a friend as a guarantor and claims that this makes it not a payday loan. This also allows the company to chase two people for the same debt.

Six years ago, it was only a notion that capping would help protect the public from these companies. Now, we have clear and independent evidence that it does. Yet while the numbers have changed, the mindset has not. Britain’s financial sector is still a culture in which regulators and politicians alike use “unintended consequences” to justify doing nothing to help stop exploitation, as if we need to wait until a certain number of people get into financial difficulties before we can act.

Expecting the public to be guinea pigs for predator capitalism is no better than acting as if it cannot be tackled. The left, at its best, has not only challenged poverty pay and provided a welfare state but also confronted rip-off practices. Our movement should not flinch in our confidence that we can reform markets, rather than simply berate them. For the sake of every cash-strapped Briton, our priority should not be to dance on Wonga’s grave, but to stop this happening again.

Yes, we should demand decent wages for all, an end to the horrors of universal credit and a cash injection into the credit union sector. But at present, you are better protected if you take out a payday loan than a credit card. Labour must lead the charge in calling for all forms of credit to be capped to stop any company pushing consumers into debt to make a profit. Our job is not done and Wonga was not a one-off. However maddening, we must not rest until Britain is a nation of shark stoppers everywhere.