Diolch, Llywydd. All wars everywhere are equally awful for the people caught up in them, but there are certain wars that carry within them seeds of destruction so universal it has the potential to consume us all. I think it's increasingly evident that the war in Ukraine is such a war, a moment in history the likes of which we have not seen for 80 years.

'Waves of anger and fear / Circulate over the bright / And darkened lands of the earth'.

Those words of W.H. Auden, written as Nazi tanks invaded Poland, could have been written yesterday, not on 1 September 1939. Like his generation, we desperately want, in the midst of this darkness, the light and affirming flame, but it's not enough just to declare our solidarity. We must act.

So, what must be done? We have to impose nothing less than a total economic embargo on Russia. It's morally indefensible to fund Putin's war machine with the purchase of oil, gas and coal or indeed wheat or chromium. The UK is offering only to end the imports of oil by the end of the year. That's a position, quite frankly, that is politically and morally untenable when children are being killed as we speak in Ukraine. We need nothing less than a full energy embargo immediately. Now, it'll be painful. We understand that. But it's technically and economically possible. The Organisation for Economic Co-operation and Development countries have a strategic petroleum reserve of at least 90 days. It's possible, therefore, and that's why we must do it. And it'll make it impossible for Putin to continue waging his offensive war in Ukraine beyond a few weeks. And we should extend it to gas as well. I mean, talking about, as the EU is talking about, reducing gas imports by two thirds by the end of the year—again, it doesn't rise to the moral imperative that we face, and it is possible to have a complete embargo on gas as well. We've had weeks of mild weather, and major deliveries of US liquefied natural gas mean that European gas storage levels are now high, and, with the summer ahead of us, we have time to source alternative supplies by next winter.

The sudden and total economic isolation of Russia, the combination of the total ban on transactions by the central bank, the ejection of Russia from the SWIFT system and a total energy embargo together have the potential to bring the regime down. We may reach the point, if we do this, where Putin cannot afford even to pay his own troops.

Half measures won't work. In 1935, when Mussolini invaded Ethiopia, the world imposed targeted sanctions but stopped short of an energy embargo. That enraged Mussolini, but didn't stop him. It propelled him to form an alliance with Germany, bringing about the conditions for world war two, which was precisely what the democratic powers were keen to avoid. Years later, he told Hitler that an oil embargo would have brought him down.

'In the space of eight days we would have had to retreat in Ethiopia. It would have been an unmistakable catastrophe for me', said the transcript of the meeting. And, by the way, China can't save Russia. The Chinese refineries aren't adapted to deal with sulphurous Russian oil, and the Transneft pipeline goes in the other direction. The Chinese don't have the tankers for it. If we don't buy the Russian oil tomorrow, then it's unsellable. And, by the way as well, this is an opportunity for us to decarbonise our economy finally. People talk about a wartime mobilisation on climate change. Well, the war's arrived, and now is the time to insulate our houses, to build up renewables and install heat pumps by the millions. 

We must stop Putin by every means possible short of direct military involvement by western countries. The west can't go to war directly with Russia over Ukraine because of the risk of nuclear escalation. By the way, in relation to the amendment that my friend Heledd Fychan will refer to, nuclear weapons in the world that we live in now with Putin are an asymmetric deterrent. They don't deter Vladimir Putin from his wars of aggression, but they deter us from doing anything about it. They empower dictators and paralyse the rest, which is why we must seek to remove them at a global level. But what we can do—