Ever since Theresa May’s premiership, I have become suspicious of the “lectern moment”. That is when the prime minister steps outside Downing Street to address the nation on Brexit. This week with Boris Johnson was no different. Like many, I was left puzzled by the prime minister’s speech on Monday. When he spoke of the “clear vision for our desired future relationship with the EU” that we now supposedly have, I could not help but ask myself what this vision was, and whether it really exists. There seems to be a disconnect between the words uttered outside No 10, and the reality we now face as a country.

Given what we know, it would be utterly reckless and irresponsible to proceed on this path

For MPs like myself, Downing Street has framed the choice as: speak your mind or keep your job. When we are made to choose between representing our constituents’ interests by taking no deal off the table, and toeing the rash party line on Brexit – even when that means losing good MPs to other parties, as with Phillip Lee today – we risk doing the very thing the public hate about politicians. Namely, failing to stand up for what’s right, and only furthering our own interests. This is a mistake I will not make.

Frustratingly, many in Westminster are still unable to face the facts on Brexit, even when they’re as apparent and clear as they are now. The sorry state of our political debate means we are reduced to the same old blame games and shouting matches that have characterised this debate from the start. Nothing of substance is being achieved or even proposed, while the country remains trapped in the Kafka-esque misery that Brexit has become. Almost two months into the Johnson premiership, there is no evidence of progress in securing a deal.

The facts, as I see them, are simple. First, leaving the EU without a deal would be a historic mistake and a catastrophe for our country and everyone living in it. Our national dashboard is already flashing red: sterling is in freefall, Britain’s economy is on the brink of recession, and sober government assessments show that no deal would cause disruption to our food and water supply, and our transport system, and access to vital medicines. Given what we know, it would be utterly reckless and irresponsible to proceed on this path.

Second, we cannot leave the EU in an orderly way before 31 October. Not only has there been no meaningful progress in negotiations at all – despite the rhetoric about finding a solution within 30 days when the prime minister visited Berlin – there simply isn’t enough time for the EU to ratify any new agreement, and for our parliament to approve it, even if a deal was struck.

This is why today’s vote, on a standing order that will giving parliament control of the order paper, is so important. It is rash and misguided to shut down all escape routes from no deal and hold a gun to our own head in the hope it will produce a deal at the last moment. This is Downing Street’s approach, and its apparent willingness to ignore parliament on this issue is nothing short of alarming. It is in the national interest to proceed sensibly, and give us flexibility as a country to find a solution. It is paramount that we do this using the legitimate democratic processes that are the bedrock of Britain’s politics and our society.

In order to do this, we must have an extension to the Brexit process, and put the decision back to the people in a referendum. That is why I am voting to stop no deal this week – because it is the right thing to do in the national interest, and because I have no mandate from my constituents to do otherwise.

• Sam Gyimah is the Conservative MP for East Surrey