Brexit Secretary Stephen Barclay has asked the EU to consider a separate agreement on citizens' rights in the event of no deal. About 1.3m UK citizens live in one of the other 27 EU member states, while the UK hosts about 3.2m EU nationals. Theresa May's Brexit deal covers citizens' rights but it has not yet been approved by MPs.
The EU has previously said the best way to safeguard citizens' rights would be to agree the withdrawal agreement. Tory MP Alberto Costa, who has campaigned on the issue, told the BBC Mr Barclay's intervention was "better late than never."
He resigned from his job as aide to Scottish Secretary David Mundell in February to put forward an amendment calling for the prime minister to write to the President of the European Council, Donald Tusk, to seek to guarantee the rights of EU nationals, even if a Brexit deal is not agreed. The amendment was put forward with cross-party backing of 141 MPs - and it was accepted by the government without a vote.
"The UK government has finally taken seriously the Costa amendment and with the spectre of no deal appearing ever closer, the UK government are worrying about how to protect the rights of British citizens in the EU," he said.