The home secretary asked officials to look into sending asylum seekers to isolated islands 4,000 miles from the UK, according to reports.
It's understood civil servants were asked to investigate how other countries manage their immigration systems.
Australia is one model, which holds asylum seekers offshore while their applications are processed.
The Financial Times reports that Ascension Island and St Helena in the South Atlantic were considered.
Suggested locations from the Foreign Office were said to be implausible.
Saint Helena and Ascension are tiny islands about 800 miles apart in the middle of the ocean, roughly half way between Africa and South America.
Labour's shadow home secretary, Nick Thomas-Symonds, tweeted: "This ludicrous idea is inhumane, completely impractical and wildly expensive. So it seems entirely plausible this Tory government came up with it."
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