Brits living in France could face the prospect of being unable to move freely to another EU member state after Brexit, after fraught talks revealed disagreements between London and Brussels.
Negotiators from the EU and the UK are concluding three-and-a-half days of tough talks in Brussels that are aimed at thrashing out a deal on Brexit.
One of the major sticking points is the rights of the three million EU nationals living in the UK and those of British nationals living in the EU.
According to the Guardian newspaper British officials raised the issue of UK citizens being able to move freely around the EU after Brexit.
EU officials then made it clear it would not allow this freedom of movement unless there was a reciprocal agreement that meant French, German, Spanish and other EU citizens living in Britain were able to leave the country but then freely return at a later date if they desire.
The UK appears reluctant to allow that to happen.
There are around 1.2 million British citizens living through the EU, including between 150,000 and 200,000 in France.
Unless the two sides reach an agreement then those Brits living in France wouldn't be able to freely move to Germany or Spain for example as they have been able to up to now.
"We would start from the assumption that in order to maintain the right of EU citizens to move around the EU 27 this would require the UK to reciprocate by allowing EU citizens to continue moving around freely," a senior EU official was quoted as saying in the Guardian.
Ensuring the rights of EU and British citizens is a top priority for both sides, but it has also proved to be one of the major sources of tension along with the so-called "divorce bill".
Last month UK Prime Minister Theresa May revealed her offer to EU citizens after Brexit, which would allow those who arrive lawfully before Brexit the chance to build up same rights as British citizens.
However her pledge was derided by both EU leaders and EU citizens living in the UK.
Their message to May was "you're going to have to do better than that".
Negotiations are set to run through the summer.