ECREU is a lobbying group aiming to gain protection for expats in the EU (which includes those living in the UK). It is essentially not anti-Brexit, but in the event of a UK withdrawal wants to see an agreement which protects expats rights gained over 40 years of membership of the EU.
Its latest newsletter has useful information on progress in various countries, including the status of ill or destitute UK citizens who want to return to Britain, who may find it difficult to get help.
Link to the newsletter (which also contains links to RIFT website - Remain in France Together- which also goes through the various deal/no deal scenarios).
https://www.ecreu.com/pdfs/ecreu-news-apr-19.pdf
