Justin Welby launches fresh attack on Rishi Sunak’s migration plan

“That cannot be done simply by cutting off people who arrive.

“It must be done by cutting them off far further back.

“To cut them off simply when they arrive is like, as in parts of the diocese of Canterbury which are prone to flooding, thinking that by putting up sandbags at the front door you can stop the water coming round the back.”

Welby added: “This Bill currently focuses solely on our domestic situation and proposes action which is not only unlikely to achieve its end domestically but also undermines the principles of the global refugee system, which the UK was influential setting up in the first place.

“It is neither morally right nor strategically sensible to fail to engage with the global context or to leave other countries to deal with the crisis alone.

“Doing so damages our reputation as a nation but it also risks unbearable pressures being placed on other countries and the possibility of state collapse and an ever-growing avalanche of further numbers of refugees across the world, adding to the problems we face.”

The House of Lords continued to scrutinise the Illegal Migration Bill during a late session held on Monday night.

The legislation, which was introduced by Home Secretary Suella Braverman, passed through the House of Commons in late April by 289 votes to 230.

It would enable the UK to detain and promptly deport those who arrive on British shores illegally.

Illegal immigrants would either be sent to their home country or to a third country, such as Rwanda.

Despite the policy facing criticism, Germany has reportedly been putting pressure on the European Union to adopt a similar scheme in a bid to curtail the continent’s own asylum crisis.

Rwanda and Niger have been earmarked as potential non-EU nations which would cooperate with the 27-member bloc.

But Welby has long-criticised the Government over the policy and tried to bolt on a series of amendments, including a 10-year strategy.

Home Office Minister Lord Murray of Blidworth claimed strategies are “not a silver bullet”.

The 48-year-old said: “A strategy in and of itself will not enhance the collective response to a particular challenge and it is a moot point whether a 10-year strategy is too long a horizon in this area.

“Policies can change with changes of government and indeed one government cannot bind its successor.

“There is also always a risk that resources are consumed preparing strategies and monitoring their implementation rather than getting on with the vital core task at hand.”

He added: “If we do not tackle and substantially reduce the current scale of illegal entry into the UK, our resources will continue to be sapped by the sheer numbers crossing the Channel, necessarily impacting on our capacity to address the strategic challenges.”