REUTERS/Eric Vidal Explained: The Brexit "backstop" and why it could be the difference between deal or no deal. The EU wants Britain to agree to a fallback option for avoiding a hard Irish border. However, the EU's demands are political suicide for Theresa May, while the UK's demands are unacceptable to Brussels. There will be no withdrawal deal unless the two sides find a compromise. LONDON — With just a few months left to run in Brexit talks, a number major issues are still a long way from being resolved.