Mr Barnier raised concerns that simply “carving” out sections of the withdrawal agreement would be too complicated and impossible to police without European Court of Justice jurisdiction afforded in the deal.
He said: “I am certainly aware of the proposal put forward by Mr costa, supported by the House of Commons on February 27.”
He added: “I have difficulties understanding how the amendment proposed by Mr Costa can be reconciled with the vote of the House of Commons on March 13 to exclude an exit from the Union without a withdrawal agreement.
“Moreover, I would like to emphasise that the provisions of the withdrawal agreement on citizens’ rights are part of an overall and comprehensive approach to the orderly withdrawal of the United Kingdom.
“Beyond the part specifically titled ‘Citizens’ rights’, the agreement contain other provisions also relevant to the protection of other rights of citizens. For instance, it also includes provisions on personal data protection, on the orderly completion of judicial cooperation procedures in criminal and/or civil maters and of administrative procedures affecting citizens, as well as provisions aimed at ensuring that there will be no hard bother between the Republic of Ireland and Northern Ireland, to the benefit the citizens residing there.
Mr Barnier claimed it would be “far from straightforward to identify which provisions would need to be ‘carved-out’ as part of the ring-fencing exercise proposed by the House of Commons in February”.
Mr Barclay has since met with campaign groups British in Europe and the 3Million to build support for the Government’s proposal to “ring-fence” citizens’ rights.
On Monday, he once again penned a letter to Mr Barnier to urge Commission cooperation for the plans ahead of Britain’s EU departure.
Mr Barclay said: “Both these groups are they that they are not asking for the withdrawal agreement to be reopened, but for the citizens’ rights agreement to be agreed using an Article 50 legal base in any scenario.
“They are clear that this offers the greatest protection to UK nationals in the EU and to EU citizens in the UK, particularly in key areas such as healthcare and pension.”
The Brexit Secretary claimed he also has support from within the European Parliament and “other member states” for his plan.
He said: “I believe we collectively have an opportunity to address these concerns and that we should make sustained efforts to do so, including by fully considering these proposals and the technical issues raised in your letter.
“I note that there is gathering support from parliamentarians in the European Parliament and other member states for so doing. For example, I am away that members of the European Parliament wrote to leaders of the institutions calling for a ring-fenced citizens’ rights agreement.”
He added: “To conclude, I agree with our joint efforts should remain focused on making sure that we reach an agreement in order to secure an orderly departure for both the UK and the EU.
“However, I suggest that together our officials continue to work on how we best protect citizens’ rights in all scenarios.”
