LONDON (Reuters) - The Brexit proposals put forward by British Prime Minister Theresa May are the only “credible and negotiable” ones, her spokesman said on Wednesday after rebels in her party presented alternative plans for the border in Northern Ireland.

“We have been working on the issue of the Northern Irish border for two years and we have looked at a significant number of potential solutions and we believe that the plan put forward by Chequers is the only credible and negotiable one,” the spokesman told reporters.