Britain's Prime Minister Theresa May walks to the Conservative Party Conference in Birmingham, Britain September 30, 2018. REUTERS/Toby Melville

BIRMINGHAM, England (Reuters) - British Prime Minister Theresa May said on Tuesday she is preparing to make a new offer to the European Union aimed at breaking the deadlock in the Brexit negotiations.

“We will be setting forwards those proposals. Can I just explain why we are setting forward our own proposals? It is because the plan the European Union put forward is not acceptable to us,” May told BBC radio.

“Because the plan the European Union has put forward is one that effectively keeps Northern Ireland in the customs union and ensures that effectively there is a customs border down the Irish sea.”