Chloe Westley is the Campaign Manager of the Taxpayers’ Alliance.

“As we leave the European Union, we will no longer be members of the Single Market or Customs Union.” That was the promise the Conservative Party made to the British electorate in last year’s general election. This was a clear manifesto commitment to deliver what 17.4 million people voted for in the EU Referendum – a clean Brexit.

Millions of people voted for the Tories because they trusted Theresa May, and every Conservative MP who stood on that manifesto, to honour it. It now seems that many people fear that trust may have been misplaced.

Up until recently, it was clear Government policy for Britain to leave the Single Market and the Customs Union. And yet Cabinet Ministers who held true to this, and who have advocated a clean break from the EU, have been described in recent weeks as ‘rebels’, who needed to fall into line and accept a soft Brexit.

The new EU policy agreed by Cabinet on Friday raises several concerns. It doesn’t appear to give Britain full control over rule-making, and it’s unclear to what extent divergence from EU regulations will be possible. Furthermore, the new customs arrangement proposed is strikingly similar to the one previously rejected by Brexiteering Cabinet Ministers for inhibiting Britain’s ability to strike trade deals with such countries as America and Australia.

Whilst most people outside Westminster won’t necessarily be on top of the details of this proposal, what may cut through is the extent to which the Prime Minister is prepared to leave some power behind in Brussels. Will Britain really be leaving the Single Market and the Customs Union, or signing up to associated membership of each? Will elected politicians in Britain be in control of our laws, or will we be ‘rule takers’ from Brussels? Will we restore control of our borders, or is Britain’s immigration policy negotiable?

I suspect that there is an assumption that by simply stating that ‘Brexit means Brexit’, the Prime Minister can advocate a soft version without the general public noticing. However, I would strongly caution against underestimating public sentiment, and voters’ interest in precisely how we leave the EU. Survation polling over the weekend that showed Labour moving into the lead for the first time since March may be evidence of this.

The decision to leave the EU was largely driven by a desire to live in a more democratic society, and for ordinary people to have more of a say in the future direction of the country. Vote Leave put it succinctly: Brexit should mean we take back control of our laws, borders, money and trade. Sadly, this deal doesn’t look like it will deliver any of those things.

On laws, the government appears prepared to be a ‘rule taker’ from Brussels and accept the superiority of the European Court of Justice in some instances.

On borders, the Prime Minister has refused to rule out special treatment for EU citizens after we leave the EU. This would mean that, far from taking back control of our borders, Britain could still have to accept some kind of free movement, and continue to discriminate against non-EU immigrants.

On money, the Government has announced they will spend the Brexit dividend on the NHS. But if we remain in the Single Market, or maintain some kind of associate membership, there will be no Brexit dividend to spend.

On trade, the Government is committed to a ‘customs arrangement’ which could seriously inhibit Britain’s ability to strike trade deals with other countries such as America.

Despite the Prime Minister’s assertion to the British public that she would honour the referendum result and commit to a clean break from the EU, we now appear to be moving in the direction of a soft Brexit. And whilst this may please the political and media establishment, it is likely to anger millions of people who already feel that politicians don’t listen to the views of ordinary people.

Polling conducted on behalf of Change Britain found that 32 per cent of voters would be less likely to vote Conservative if the Government agreed a deal which results in UK laws being subject to rulings by EU courts. And more than a quarter would be less likely to support the Conservatives if Brussels maintained some kind of control of the UK’s ability to sign free trade agreements with other countries.

When the Liberal Democrats betrayed their pledge not to raise tuition fees, they were punished by the electorate in 2015. Brexit is, of course, even bigger than that.

Many of the 17.4 million people who voted for Brexit wanted Britain to become an independent country. They thought that vote would mean something.

If the Conservatives forsake their election pledge to deliver a clean Brexit, they don’t only risk losing future elections, but may for decades struggle to shake off the image of betraying the largest democratic vote in British history.