British Prime Minister Boris Johnson said that with energy and creativity, he’ll be able to find an alternative to the Irish backstop.

He’s been meeting European leaders to try to get the backstop struck off Britain’s withdrawal agreement from the EU.

What exactly is it, and why is it key to the Brexit process?

CGTN’s Gerald Tan reports.

To understand the backstop is a short lesson in history and geography.

Northern Ireland is part of the United Kingdom. The Republic of Ireland isn’t but is a member of the European Union.

They share a land border, and right now, while Britain is still in the EU, goods, and people can move seamlessly between Northern Ireland and the Republic. That changes once Britain leaves the EU.

The backstop is a safety net negotiated between former British Prime Minister Theresa May and EU leaders. It preserves the seamless border between Northern Ireland and its southern neighbor on one condition: even after Brexit, the U.K. must still obey EU customs regulations and other rules.

But there’s a new Prime Minister now.

“The existing agreement doesn’t work for the UK, and Parliament has thrown it out three times. We can’t have this backstop,” Johnson said.

So why the controversy? A return to a hard border undermines principles set out in the 1998 peace agreement, which ended a 30-year, sectarian conflict in Northern Ireland.

But without security checkpoints, the U.K. must remain in the EU Customs Union after Brexit.

Johnson firmly opposes the backstop and calls it anti-democratic. He’s now on a collision course with EU leaders – who said he’s not presented a viable alternative.