Britain's Crown dependencies have written to David Cameron requesting a seat at Brexit negotiations despite already being outside the EU.
The chief ministers of Jersey, Guernsey and the Isle of Man said the islands had a "direct interest" in the UK's withdrawal because it would affect their trade arrangements with the EU.
People in the Crown dependencies were not eligible to vote in the referendum.
Mr Cameron told the House of Commons on Monday the islands would be consulted.
In the open letter published on Tuesday the leaders of the Crown dependencies said they wished to "retain the status quo" regarding their relationship with the EU, in particular concerning their Protocol 3 deal.
Protocol 3 - the section of the UK Treaty of Accession relating to the Crown dependencies - currently allows the islands to have free trade of goods with the EU but will be nullified when the UK formally leaves the union.
Decisions concerning rights for EU nationals were also "of particular relevance" to the Crown dependencies because they "are home to a significant number of non-British EU nationals and residents that have EU rights through their connection to the UK", the letter said.
The leaders asked the prime minister to confirm that the islands would be "kept informed on matters of interest to us" and to be allowed to contribute to negotiations "where appropriate".
However, the chief ministers stressed their "closest relationship is with the UK" and they understood that Brexit would not prevent free trade and free movement of people between their jurisdictions.
The BBC has approached the prime minister's office for comment.