Safe Third Countries
If an asylum seeker passed through another country on the way to the UK, the Home Office may attempt to remove them to that country under the Dublin II Regulation, which is an EU law setting out the rules for deciding which EU country should decide an asylum application. The Dublin II Regulation is based on the principle that the first European Union country which the asylum seeker entered into should decide their asylum claim.
Some non-EU countries are also deemed to be safe in the sense that it is assumed they will decide asylum claims in the same way that the UK would. Lists of safe third countries are made under the Immigration and Asylum Act 1999 s 12 and delegated legislation, e.g. the Asylum (Designated Safe Third Countries) Order 2000 SI 2000/2245.
Link to Home Office website which provides Policy instruction on safe third country cases.

