Britain's Prime Minister, Theresa May, leaves 10 Downing Street, to make a statement in the House of Commons, in London, Britain November 15, 2018. REUTERS/Peter Nicholls

LONDON (Reuters) - British Prime Minister Theresa May said on Thursday she shared the concerns of those who believe a Brexit backstop to avoid a border on the island of Ireland impinges on British sovereignty, but it was an improvement on previous proposals.

“The references to the backstop do raise some difficult issues,” May told parliament.

“I fully accept that across the house, there are concerns in relation to the backstop. Indeed, I share some of those concerns,” she said.