Attorney General Sir Geoffrey Cox, pictured, is attempting to write a codicil to the Government's Brexit withdrawal agreement with the EU which will alleviate concerns of Tory back benchers to the Northern Ireland back stop Hopes of breaking the deadlock over the controversial Northern Ireland backstop rest on Attorney General Geoffrey Cox's legally binding addition to the Brussels divorce text. The document, called a codicil, is the subject of intensive talks between British and EU negotiators as Brexit Day approaches. Sir Geoffrey, the Government's top lawyer, sunk Mrs May's first attempt to get her Brexit deal through the Commons after his legal advice said the UK could be trapped in the backstop indefinitely. He has now presented the codicil to Brussels – and, if it is accepted, it would allow the respected QC to change his advice to MPs. However, the codicil falls far short of the fixed-time limit on the backstop demanded by Brexiteers, who have already mockingly dubbed the legal document 'a codpiece'. However, the EU chief Brexit negotiator Michel Barnier has indicated he does not believe the UK will have enough time to approve Theresa May's withdrawal deal by the scheduled exit date of March 29. Mr Barnier suggested a 'technical extension' of up to two months may be needed. The Prime Minister has told MPs they will have a 'meaningful vote' on her withdrawal plans by March 12. Asked if he thought it was possible to reach an agreement by March 29, even if Westminster gave the green light this month, Mr Barnier told Spain's El Mundo newspaper: 'No.' Referencing a technical extension, Mr Barnier added: 'But you'll have to ask the United Kingdom. If there is a vote on the 12th and it takes two months to carry out the procedure, it would be justified.' Mrs May has said that if her deal is rejected by Parliament, MPs will be able to vote on whether the UK can leave the EU in a no-deal scenario, and if that is rejected, the Commons can decide on whether to extend Article 50 and delay Brexit for a limited period. EU Chief Negotiator Michel Barnier said he did not believe Britain will be in a position to leave the EU on March 29 and will require an Article 50 extension Mr Barnier has also stated that Brussels is ready to give the UK further 'guarantees, assurances and clarifications' that the Irish backstop should only be temporary. He insisted that the controversial measure, intended to avoid a hard border on the island of Ireland, will not be removed from the Withdrawal Agreement. While acknowledging Brexiteer concerns that the backstop is a trap that would keep the UK tied to the EU indefinitely, Mr Barnier insisted it is only 'insurance' intended for the 'worst-case scenario'. Speaking to German newspaper Die Welt, Mr Barnier said: 'We know that there are misgivings in Britain that the backstop could keep Britain forever connected to the EU. 'This is not the case. And we are ready to give further guarantees, assurances and clarifications that the backstop should only be temporary.' The guarantees in question could come as an adjunct to the Withdrawal Agreement in the form of an 'interpretive document', he said. However the EU will not allow for a time limit to be placed on the backstop or give Britain the right to unilaterally pull out of it, Mr Barnier added. The development came as the president of Slovenia suggested the country and many other EU states would be willing to accept a short delay to Brexit. Borut Pahor, who sat on the European Council of leaders when he was prime minister, told Sky News: 'I think Slovenia and a lot of other countries would say yes. 'I think that nobody wants to see a hard Brexit in a chaotic way, which would damage London and Brussels and Ljubljana and every country.' However Mr Pahor said the extension should not be used simply to postpone the making of a compromise decision. Mrs May has insisted she does not want a delay Brexit and believes the UK can leave the EU as scheduled on March 29. Meanwhile, Jeremy Corbyn confirmed Labour would now back a referendum if faced with a 'damaging Tory Brexit' or a no-deal departure from the European Union after Labour's vision was rejected in the Commons. Chief Secretary to the Treasury Liz Truss warned on Friday that a new Brexit referendum would provoke a 'massive crisis'. She also indicated that a no-deal exit could be better than a delay. Ms Truss told the BBC: 'I think it would be an absolute disaster if we had a second referendum after people voted so clearly to leave the European Union. 'There will be a massive crisis in this nation. And it would be terrible for business. It would leave us continuing in this limbo period.'All rights reserved for this news site dailymail and under his responsibility