Starmer might be "mr inaction" but why are the UK Gov not announcing:
"The invitation to the PResident of the US for a Royal State Visit ihas been put on hold pending a review. Royal State visits are an honour offorded only to our closest allies and recent actions by the President of the US are not those of an ally to the UK".
Not starting a trade war, pointing out to Trump Starmer is not just clutching his ankles (again) and welcoming any and all bullying. And the "review" can always conclude that Trump has acting in some unforeseen beneficial manner and the State Visit is progressing.
As things stand with what I've seen of UK public opinion (polls) Trump turning up for a satte visit would not go down well and would further turn public opinion away from Starmer/Labour.
Ian