The Prime Minister also signaled moves to end housing asylum seekers in expensive hotel accommodation by creating purpose-built Greek-style reception centres to hold illegal arrivals and expanding detention centres.

He admitted transporting migrants to Rwanda was not a magic bullet for tackling the problem of illegal migration across the Channel, but added: “I profoundly believe there is simply no other option. And I say to those who would criticise our plan today, we have a plan – what is your alternative?”

Mr Johnson accepted that the controversial pushback policy – under which migrant boats are turned back at sea by Border Force jet skis – could only be deployed in “extremely limited” circumstances. “Relying solely on this course of action is not practical, in my view,” he said.

Instead, he said he believed the Rwanda option would act as an effective deterrent, adding: “It’s to get into the heads of people who are coming across the Channel, risking their lives in this way, that they’re much much better off going for the safe and legal routes we have rather than paying to jump the queue.

“Because if they come across the Channel illegally in these vessels then they risk ending up not in the UK but in Rwanda. That is something I believe will over time prove a very considerable deterrent.”

He urged critics “not to think in a blinkered way about Rwanda” and said: “Rwanda has totally transformed over the last few decades, it’s a very, very different country from what it was. This is not something that we’ve put together overnight – this has been nine months in preparation.”