When we meet in London this week I have a simple message for Jeremy Corbyn: back Remain or back someone else who does.
This is not a time for political posturing. There is too much at stake. We are now less than ten weeks away from Boris Johnson’s Brexit day.
Nothing we’ve seen from the new prime minister has indicated his eyes are set on anything other than a disastrous crash out Brexit that will cause massive damage to Wales’ communities and businesses.
Under my leadership, Plaid Cymru has taken the strongest anti-Brexit stance, making it clear we fully support a People’s Vote and calling out non-committal Labour in the parliaments in Cardiff Bay and Westminster.
Our clarion call for Remain won hugely increased support in May’s European election in Wales. It was followed by a positive move in the spirit of co-operation and unity when we stood aside in the Brecon and Radnorshire by-election last month.
That unprecedented move allowed the pro-Remain vote to successfully coalesce around a single anti-Brexit candidate. The result showed that, numerically, it was our loyal support that tipped the balance against a Brexiteer Conservative.
Our priority in all this is, and always has been, the Welsh national interest. We are prepared to do whatever it takes to protect Welsh jobs, our communities, our farmers, and our ports.
In just over a week’s time, the Westminster parliament will reconvene, and it looks all but certain that Boris Johnson will face a vote of no confidence from the opposition parties.
Labour leader Jeremy Corbyn has said that he would be prepared to form a time-limited caretaker government with a view to securing an extension and holding a general election.
But what Mr Corbyn must understand is that he cannot seek to become prime minister if his caretaker administration would offer no more certainty of ditching Brexit than the current one.
I approach his proposition with an open mind, but also a healthy dose of scepticism. Mr Corbyn’s public pronouncements have thus far failed to convince me, or indeed even some on his Front Bench.
With time running dangerously short, Mr Corbyn must realise that we would not be able to back him unless he makes a totally unqualified commitment to Remain.
Just this week, Mr Corbyn failed to confirm that a Labour government under his leadership would campaign for Remain in a second referendum if a deal negotiated by Labour were also on the ballot.
I’m afraid I must say to Mr Corbyn that he cannot expect to become prime minister and then seek to secure a ‘better’ deal to put on a referendum ballot paper, when no such deal exists.
So I want to be clear with him: if he wants our backing to be prime minister, he has to commit fully and unreservedly to keeping Wales, and the rest of the UK, in the European Union.
There can be no more prevaricating or flip-flopping. There can be no more muddiness or confusion over Labour’s position. There can be no more yo-yoing between a Labour Brexit and Remain.
A prospective prime minister, even a caretaker, also needs to set out his wider vision for our country. We in Plaid Cymru could never support a British prime minister who does not present a programme for full devolution and economic justice for Wales.
We believe an immediate programme of radical redistribution to the left-behind communities that voted Leave culminating in a new referendum is better than a snap election called at the No Dealers’ behest.
But in these polarised political times, the antidote to a Tory prime minister hellbent on crashing out of the EU is certainly not a Labour prime minister intent on further prevarication.
Rather, it is a prime minister who is prepared to put a stop finally to this Brexit chaos by clearly coming out for Remain.
If he is unprepared to do this, then I’m afraid Mr Corbyn will find himself unable to command the confidence of the House in order to become prime minister.
In such an event, he must be prepared to allow someone else to attempt to form an alternative government.
Ultimately, this isn’t a question of personalities – it is one of policy. If he isn’t able to rise to the occasion, then someone who can should be given the opportunity.
We are, in the meantime, seeking to build a broad-based Remain alliance. If Mr Corbyn made Labour a true party of Remain he could yet be part of it. We could work together to make Wales a Tory and, therefore, Brexit-free zone.
This would have to mean Labour becoming both clear and collaborative – two characteristics which have been sorely lacking in Labour’s approach to date.
How Labour approaches the confidence vote will seal the fates of both Mr Corbyn and Mr Johnson. But much more importantly, the livelihoods of millions are hanging in the balance.
The Party of Wales will always put Wales before Party. Can the People count on the People’s Party to finally do the same?