Lambeth council is to fund local charities to advise European Union nationals living in the borough about their future status in the UK.
There are an estimated 40,000 EU nationals in the borough, including significant Portuguese, Polish, Italian, Spanish and French communities.
The legal right to live in Britain as a European citizen, or a non-European family member, will end for most of them on 30 June.
A successful application to the European Union Settlement Scheme allows EU citizens to continue to live, work and study in the UK without any immigration time restrictions.
Applications are free and straightforward and many Lambeth residents have already applied.
However the council is concerned that not everyone who needs to apply is aware of the requirement, and also that some eligible residents need help to complete their applications.
In response, it is investing £136,000 to ensure as many eligible residents as possible apply to the scheme.
The council says this will boost the amount of help and support available for local people. Phone and online services, one-to-one appointments and specialist legal advice to help with complex cases will be available.
There will also be extra support for vulnerable social care users who need to apply to the scheme.
Cllr Donatus Anyanwu, council cabinet member for voluntary sector and leisure, said: “We are clear, we want our European citizen residents to stay, even though we have left the EU, because we value their huge contribution to this borough.
“We are focussing on ensuring as many people as possible from our diverse communities are able to access the system established by the government.
“By partnering with well established local charities with a strong track record of supporting our communities we can help make sure people can secure their rights to stay.
“We know that for many people applying for settled status will be a straightforward task, but that for some there may be challenges.
“That’s why we are working to ensure equality of access for all.”
Council leader Jack Hopkins said: “Our greatest asset is our diversity, and we value all of our communities, including all of our residents from the European Union.
“In Lambeth, our EU citizens are an integral part of our communities and make an invaluable contribution to our businesses, the delivery of our public services, and to wider public life.
“While Lambeth was the borough in the country that voted most heavily for Remain – and as a council we are immensely proud of that – we have now left the European Union and are working to manage the impact and uncertainty that has resulted.”