Fictitious scenario. The date is Monday 22 July, the day before Boris Johnson is expected to be approved leader of the Conservative Party, and two days before he is expected to go to the Palace to see the Queen. Jeremy Corbyn announces he will make a public speech, explaining Labour’s position. This is what he ought to say.

Ladies and gentlemen,

Thank you for taking the time to come here today. I think that you, like me, realise this is a crucial moment for our country. We face two major headaches – that Boris Johnson is likely to become leader of the Conservative Party, and that he seems intent on taking the UK out of the European Union without a Deal on 31st October.

Both of these things – the damage such a right wing Prime Minister would do to our country, and the havoc a No Deal Brexit would wreak – are neither things that the Labour Party can tolerate.

No Labour leader, front bencher, MP, party member or union member should support either. Both endanger the lives of the very weakest in our societies, those that are least able to defend themselves. We must fight against both with all of our might.

My message to my Labour colleagues who have in recent weeks been saying they would be reluctantly be able to agree to a No Deal Brexit is this: could you look the worker at a car plant in the eye and say yes, your job will be in danger? Or tell a father of young children, struggling to make ends meet, that costs in his local supermarket will shoot up? Or tell a nurse that the predicament in the NHS will worsen?

Because that is what No Deal Brexit will mean.

However there are some things about the 2016 referendum that I do acknowledge. A small majority of the British population did vote to leave the European Union. And something like two thirds of Labour MPs represent seats where there was a majority for Leave.

But we also know that four fifths of Labour party members are still pro-EU, and a majority of Labour voters voted Remain in the 2016 referendum.

And there are still many unanswered questions about the very conduct of that 2016 referendum.

In the wider population – as we saw at May’s European elections – positions have hardened. The divide grows ever further between determined pro-Brexit and determined pro-Remain voters.

And that divide grows within our party as well.

And the clock still relentlessly ticks down to 31st October.

So what do we do?

First, as Leader of the Opposition I will table a Vote of No Confidence in the Government on Wednesday morning. I expect every Labour MP to back this, and any that do not will immediately have the whip withdrawn and those MPs should consider that they will not be welcome to stand as Labour candidates at a forthcoming election.

The clear aim this week is to stop Boris Johnson becoming Prime Minister and inflicting further austerity on the country. Every single Labour MP must stand in his way.

Second, if that No Confidence Vote succeeds, Labour’s priority is to force a General Election to take place. We will not back any efforts to form some sort of national unity or interim government. We need to end Tory-imposed austerity once and for all. I am aware a fortnight is foreseen in the Fixed Term Parliaments Act, but we intend to sit that out.

Third, we will pursue a dual strategy on Brexit. We will demand changes to the Brexit deal that is on the table to ensure that the UK can stay permanently in a Customs Union with the EU, and that the Brexit on offer is more in line with Labour’s demands. And, conscious of what has happened the past three years, will demand a referendum on any Brexit deal – but that does not mean No Deal, as we see leaving the EU with a negotiated deal as the only viable option. Any referendum must be a negotiated Deal versus Remain.

Organising such a referendum will take months, so we will ask for extra time from the European Union to allow it to be organised.

However we will not put any resources from the Labour Party into the referendum campaign to come, and Labour MPs will be free to campaign for or anti Brexit as they see fit.

I understand some colleagues might have problems with this approach, but in response I say this: what was offered to the people in 2016 has not come to pass. A 52 to 48 vote in favour of a Brexit proposition that, we now know, is not available, surely justifies a further referendum. But likewise Labour MPs promised to respect Leave voters’ choices – that is why Labour MPs will be free to campaign as they see fit in this confirmatory referendum. If you voted Leave in 2016, go again and do so in the confirmatory vote. And then with a clear mandate – either for a clear Brexit proposition or for Remain – Labour stands ready to implement either.

As Harold Wilson once famously said, “The Labour party is a moral crusade or it is nothing.” Our morals are to protect the poorest in society, and that means No Boris Johnson as Prime Minister, and No No-Deal Brexit. We do not have a moment to lose.

Thank you!