Theresa May is to offer free movement to Irish citizens in and out of Britain after the UK leaves the European Union, the Sunday Telegraph can reveal.

News of the offer of a “Schengen area” between Britain and Ireland came as the Government prepares to publish a formal proposal to the EU on the future of the Northern Irish border.

Britain will also offer to track goods being moved in vehicles across the Irish border with CCTV cameras and automated number plate technology as part of a light touch customs regime.

That will come alongside other documents setting out how Britain’s involvement in the customs union with other EU countries this week. More papers on fisheries and agriculture will be published next week.

Other papers about the continued availability of goods for the EU and the UK, and confidentiality and access to official documents after Brexit will also be published.