Under new UK-wide arrangements instigated by the Home Office, advice services for those going through the asylum system will be transferred from Scotland to Kent from Tuesday, where they will be run by the charity Migrant Help.
But the new system will not carry out advocacy work, such as helping asylum seekers who have been refused permission to stay in the UK appeal, or chasing decisions on applications for financial and accommodation support.
Critics said asylum seekers will find it difficult to get adequate support as services will now be provided through a website and a telephone helpline based in Dover, rather than the previous face-to-face service provided in Glasgow.
The Scottish Government has pledged to monitor the new contract and said it will raise any concerns with the Home Office.
For the past 14 years, the Scottish Refugee Council (SRC) provided asylum advice services in Scotland through a drop-in service, with around 30 people a day attending.
Gary Christie, head of policy at the SRC, said: "Previously we have had full flexibility to meet the needs of people coming through the asylum system.
"There is concern about the lack of face-to-face sessions. They come with different levels of English … for many of them, having to phone up somebody or go on to a website will mean they have difficulty accessing advice.
"The fear is that applications will not be made for asylum support and potentially more people will fall into destitution, even when they have a right to be accessing support."
The exact numbers of destitute asylum seekers in Scotland is not known, but one survey in 2012 identified 140 people seeking help from asylum seeker or refuge support agencies over just one week as being destitute.
Migrant Help will run two services, providing advice to those making applications for asylum and also to asylum seekers seeking financial and accommodation support. But it states that advocacy - charity staff speaking on behalf of an asylum seeker, as was done by the Scottish service - is excluded from both services and clients will need to be referred elsewhere.
Christie said: "There can be major delays in the Home Office making a decision on whether somebody should be receiving support or not, for example. What we would do is to chivvy the Home Office and say, 'Where is this application at and what are you doing about it?' That is just not within the specification of the new service."
He added: "If someone is refused asylum support they can appeal to a tribunal down in London. But supporting somebody through that process … will not be within the specifications of this new contract.
"People who have been denied support, who should be getting support, will potentially fall through the net."
A spokeswoman for the Scottish Government said the SRC had a "strong history" of providing expert advice and support to asylum seekers dispersed to Scotland.
She said: "It is regrettable that the SRC has lost the contract to provide invaluable advice to vulnerable asylum seekers arriving in Scotland. We will monitor the situation once the new contract is in place and, if any gaps in service are apparent, we will raise this with the Home Office."
Migrant Help, which describes itself as a non-campaigning charity, said its Asylum Help services would be provided through a variety of methods.
Asylum seekers outside the southeast of England will be given an initial interview by Migrant Help staff in offices in Liverpool, Birmingham, Glasgow, Wakefield in Yorkshire, Belfast and Cardiff. However, from then on, advice and guidance will be through the free telephone helpline and website, with information made available in 15 languages.
A Migrant Help spokeswoman said: "Our advisers will offer demand-led outreach services to vulnerable clients, clients with special needs and those who are unable to access the telephone or online advice.
"Clients who require advocacy services will be referred to another voluntary sector organisation or a legal representative as appropriate."
A Home Office spokesman said funding for the services had not been cut and it was committed to an asylum support system that "meets the essential needs of asylum seekers".
He added: "We are clear that those who do not need our protection should return home. If failed asylum seekers are unable to return home for reasons beyond their control, we will provide support to ensure they are not destitute."