The phoney war is over. Parliament has signalled that it supports article 50 being triggered. We are leaving the European Union. The pretence that this was at risk was used by some to argue that those questioning the government are somehow unpatriotic Brexit-deniers. This illusion can now end and the real debate over what Brexit means can begin.

Polling of Brexit voters by the Open Britain campaign shows half are not prepared to be a penny worse off as a result of leaving the EU. That includes 59% in the north; 62% of Labour Leave voters; 46% of Conservative leavers; and even 39% of Ukip voters. Only one in 10 Brexit voters is prepared to lose more than £100 a month.

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This chimes with the experience in my constituency, where seven in 10 voted to leave. Many of them were desperate for a new beginning for themselves and their families. The government will rightly be subject to an almighty backlash from Leave voters if it makes decisions that make them far poorer and leaves less money for public services. Having voted for a better future, for them this would be the ultimate betrayal. So, the onus is on the government to ensure a Brexit that is fair to working people.

The reality is that there are very difficult trade-offs and risks ahead which the government has completely failed to acknowledge. It must now make choices to minimise those risks, centring on our relationship with the single market and EU customs union. We should be aiming to remain in both. If the latter is not possible, we should, as Keir Starmer has said, seek to emulate, as closely as possible, the current arrangements for tariff-free trade in goods and services.

It will be hard to achieve this, but there are three reasons that the government’s approach makes this less likely and will leave the country significantly worse off.

Both Labour and the Conservatives have said they want to change the way freedom of movement operates. Following the referendum, I agree that there does need to be change. But there is a wide spectrum of approaches and the government appears to be basing its stance on the undeliverable promise to get net migration into the tens of thousands. Given the trade-offs in the negotiations, this will make it much harder to get single market-style arrangements.

The government is gripped by a dogmatic obsession with the evils of European law and EU standards Ed Miliband

Second, the government is gripped by a dogmatic obsession with the evils of European law and EU standards, which will drive it further away from the single market. But its dogma is absurd and self-defeating because the reality is that any company or country exporting into the single market faces those standards.

The third point is that too many people within government are convinced by grandiose fantasies about the trade deals that we can immediately do, without any evidence. They are drastically underestimating the economic dangers of leaving the customs union. The real risk is that on the back of this fantasy, our companies face bureaucratic obstacles which will make us much poorer and discourage foreign investment.

If it continues with this approach, it will be impossible for the government to put the economy first. So it must publish a real, honest plan – preferably in the form of a white paper – for which it gets a mandate from the Commons before the talks begin.

The stakes that face the country could not be higher. Voters on both sides of the issue share a desire to put our economy first. The government must protect our economic future and address the deep concerns about our unequal country that drove Brexit. Parliament and the country will hold them to account in the weeks and months ahead.

Ed Miliband is MP for Doncaster North and a former Labour party leader.