As per Skwawk article:

.. committed to at least £87bn of government spending on weapons

Apart from the fact that this is morally indefensible, it is unlikely to happen imo. I heard elsewhere that there was a caveat where he said 'if economically viable' or words to that effect. I think it is all 'gung ho' talk before NATO summit.

Regarding Zelenski .. as a hell of a lot of politicians have been toppled after meeting up with Z, there is a meme going around about 'Zelenski's curse'. Starmer joins the crew