Of course there's not.
However, we do need to find a way to stop the boats and the drowning. If people knew with absolute certainty they wouldn't get to stay in UK if they arrived on a small boat, would that stop them taking the risk?
Could that work, alongside proper safe routes for those with genuine claims - which of course is the flaw in the current plan? That and the fact that the policy would need to be applied every single time for it to work and we know that won't happen.
How do we stop the boats?