Former Prime Minister Theresa May rejected a no-deal Brexit after she was warned about the potential for terrorist attacks in Northern Ireland, according to her de facto deputy.
In his first interview since stepping down as an MP, David Lidington told The Times that Mrs May ruled out a no-deal Brexit after meeting community groups and PSNI chiefs in Belfast in February.
He said after the former PM met moderate nationalists, her fears about the threat to the Union were only strengthened, as "the prospect of a no-deal was driving them towards actively supporting a united Ireland, rather than being content to let sleeping dogs lie".
The former MP did not believe friction over the border would be a cause of violence, but "people who are inclined that way would seize upon any opportunity... it would be a grievance they could exploit".
"Anything on the border itself, even cameras, was certain to produce an increase in tension. I sat in meetings in Newry and Co Fermanagh and I was told in no uncertain terms."
Mr Lidington also said that a "fragile political situation" would have been made worse and the PSNI said the risks of public disorder "were a serious worry".