BRUSSELS (AP) — British lawmakers are meeting the European Union's chief Brexit negotiator, seeking an iron-clad guarantee that 1.3 million U.K. citizens in the bloc won't have their rights removed and lives disrupted in the event the country leaves the EU without a deal.

The rights of U.K. citizens living in the 27 other EU nations, and of 3 million EU nationals in Britain, are one of the key issues of Brexit.

Their rights to live, work and study are protected under an agreement struck between the two sides — but it has been rejected by Britain's Parliament, raising the prospect of a no-deal Brexit.

Conservative lawmaker Alberto Costa, who is leading the delegation to meet negotiator Michel Barnier in Brussels on Friday, says "If there's no agreement, there's no protection."