BRUSSELS (Reuters) - There is  no possibility  that Britain and the European Union can conclude a free trade agreement by the time Britain leaves in March 2019, EU Brexit negotiator Michel Barner said on Tuesday. Asked about suggestions in London that a trade deal could be ready for signature shortly after Britain is no longer an EU member, Barnier reiterated the EU s official line that only a  political declaration  outlining future trading relations would be ready at the time of Britain s withdrawal. He told reporters after he had briefed EU ministers ahead of a leaders  summit on Friday that negotiating a free trade pact would take longer.  He also stressed that there must be  no backtracking  by Britain on an outline divorce package agreed last week if it wants to negotiate the future relationship. He said that after the summit he hoped he would be able to present draft language early in the new year on the withdrawal treaty, elements of which were agreed last Friday. 