City of Sanctuary cannot provide any legal advice, or recommendations for legal help for immigration.
Asylum Aid can provide free, confidential legal advice and representation for asylum seekers and you can talk to them over the phone. They do not provide interpreters, so it helps to have an interpreter if whoever is seeking help does not speak good English.
The British Red Cross provides refugee support services in specific areas of the UK but cannot provide legal advice or representation.
The Refugee Council has a directory of services across the UK.
The Migrants Law Project has factsheets available on different topics, including the basic principles of asylum law.
The Refugee Phrasebook has a Juridical Phrasebook including useful words and phrases in a variety of different languages (this is under development and they need help to build some languages).