Former Brexit Secretary David Davis | Jack Taylor/Getty Images David Davis: Barnier saw Irish border issue from ‘nationalist perspective’ Idea of holding a referendum on status of Northern Ireland has ‘floated around’ EU, ex-Brexit secretary says.

BIRMINGHAM, England — Michel Barnier had a "tendency" to view the issue of the Irish border "from the nationalist perspective," former U.K. Brexit Secretary David Davis said Sunday, adding that the U.K. found it "difficult" to engage with Dublin on the issue in his final months in government.

The idea of holding a referendum on the status of Northern Ireland had "floated around" the EU, Davis told POLITICO's Jack Blanchard at the Future of Britain post-2022 event at the Conservative party's conference. But he said EU negotiator Barnier had never personally raised such an idea with him.

"There was a very large tendency for him to see the Northern Irish issue from the nationalist perspective," Davis said.

His comments reveal the extent to which the U.K. and EU negotiating teams struggled to see eye-to-eye on one of the most critical elements of the Brexit talks.

Davis said it was important to see both the nationalist and unionist point of view on the border. Theresa May's government has, since 2017, relied on the votes of the Northern Irish Democratic Unionist Party to command a majority in parliament.

He added that relations with the Irish government over Brexit had changed significantly since Leo Varadkar took over as prime minister, or Taoiseach, in 2017.

"In the beginning when Enda Kenny was Taoiseach, we were talking quite a lot to the Irish government itself," Davis said. "More recently in the run-up to Christmas and thereafter, it was quite difficult to get technical engagement with the Republic of Ireland. This is very important because the answers are largely technical."