Just two days short of Christmas, 23 December marks another, less pleasant anniversary – six months since Britain voted to leave the European Union. A few weeks after that, I co-founded the Vote Leave Watch campaign to hold the Leave campaigners to account, particularly those who found themselves in the new government, with the power to fulfil the promises they made during the campaign.

With this extraordinary year coming to a close, let’s look at those promises that were made by the likes of Boris Johnson, Liam Fox and Michael Gove, and measure them against the reality, six months on. What you will see is that the last six months have been characterised by broken promises, cold reality contrasting with their blithe assurances, and an arrogant belief that the British people have forgotten about the pledges made during the Brexit campaign.

Vote Leave’s most visible promise was to spend £350m more a week on the National Health Service. It bears repeating that five current cabinet ministers, along with many other mostly-Conservative MPs, looked the British people in the eye and promised them a huge funding boost for our cash-strapped NHS. They cannot wriggle out of this. Since the referendum, the Prime Minister has failed to commit to the promise, which did not provoke a word of protest from her pro-Brexit ministers. The Office for Budget Responsibility has forecast a £58.7bn black hole in the public finances which is directly attributable to Brexit. The Chancellor ignored the wishes of thousands of people who called on him to use the Autumn Statement to commit to the promise once Britain leaves.

Both Leave and Remain voters will rightly be angered by this betrayal. This may be the age of post-truth politics, but we are not going to forget such a visible promise. Focus groups suggest that the biggest disappointment for voters in the aftermath of the Autumn Statement has been the failure to spend any more money on the NHS. They need to be held to account for it.

Meanwhile, inflation has risen and growth forecasts have been slashed – not "scaremongering" but reality. It turns out the economic experts may have had a point. The government has refused to honour Vote Leave’s commitment to scrap VAT on fuel bills. Priti Patel has declined to repeat her pledge to use some of the savings from Britain’s contribution to create new primary school places. Perhaps most shamelessly, Boris Johnson has become a supporter of Turkey’s bid to join the European Union. Vote Leave, it must not be forgotten, said that EU membership would mean 76 million Turkish people potentially flocking to Britain as soon as the year 2020. While the Prime Minister has repeated Vote Leave’s commitment not to use Brexit as an excuse to slash workers’ rights, senior Leavers like Michael Gove do not share her sense of restraint.

With the pessimistic economic forecasts, and the growing realisation in government that Brexit will be a long and difficult process, the coming months will doubtless see yet more on Vote Leave’s promises turn into dust. The task for the progressive left must be to expose these lies and hypocrisies; vigorously oppose a government dancing to Vote Leave’s tune; and craft a vision of Brexit that will protect jobs and keep Britain a confident, ambitious, and forward-looking country.