evidence: The border between Northern Ireland and the Republic of Ireland is currently more or less invisible. There are no border controls meaning goods and people move freely to and from the neighbouring countries. [...] This is deeply important to the UK economy. A House of Lords report published in December said that €60 billion is traded between the UK and Ireland each year, and an estimated 30,000 people cross the Irish border every day. A hard border would put this at risk. [...] How this would be managed is unclear, as any kind of open border between Northern Ireland and the Republic of Ireland would mean that the UK would still have an open border with the EU, making stopping free movement impossible.