Following criticisms from the Archbishop of Canterbury, the Government has denied that it is "outsourcing" by sending migrants to Rwanda.
The Most Rev Justin Welby spoke out against the new proposals during his Easter sermon, saying the UK was "subcontracting out our responsibilities, and that the move "raised serious ethical questions".
The £120m scheme was announced last week, triggering significant criticism.
Under the new plans, those who are deemed to have entered the country illegally will be transported to the east African nation of Rwanda before being able to apply to live in the UK.
Rev Welby said: "He added: "The details are for politics and politicians. The principle must stand the judgment of God, and it cannot.
"...And it cannot carry the weight of our national responsibility as a country formed by Christian values; because sub-contracting out our responsibilities, even to a country that seeks to do well like Rwanda, is the opposite of the nature of God, who himself took responsibility for our failures."
His sentiments were echoed by his predecessor, Dr Rowan Williams.
In an interview with Times Radio the former Archbishop of Canterbury said: "Is the policy sinful? I think, in a word, yes. I think that without commenting on the motivation or moral standing of any individual involved, the policy itself seems to me to be not in accord with what I understand about God."
The Archbishop of York, Most Rev Stephen Cottrell has also chimed in on the plans, saying: "We can do better than this."
However, home secretary Priti Patel has fought back against the "institutions" criticisms via an article in The Times. It reads: 'We are taking bold and innovative steps and it's surprising that those institutions that criticise the plans fail to offer their own solutions.'
Government Minister Greg Hands has stood by decisions made by Patel, and echoed challenges for the senior clergyman to come up with a better plan.
The energy minister told Sky News: "No, we're not. This is an agreement between two sovereign countries, the UK and Rwanda.
"I think what others, the critics of this plan, need to do is to show what their solution would be."
Cabinet minister Jacob Rees-Mogg said that the Archbishop of Canterbury has misunderstood the aims of the policy.