By , LONDON/BRUSSELS (Reuters) - Britain insisted on Sunday that the European Union should shift position to open the way to a post-Brexit trade pact, drawing a swift response from the bloc’s negotiator defending the union’s right to protect its interests.Negotiations are expected to continue on Monday, beyond a Sunday deadline set by the European Parliament, and a senior British government source described them as “difficult” because of the “significant differences” in position.With less than two weeks before Britain leaves the EU’s orbit, both sides are calling on the other to move to...…By , LONDON/BRUSSELS (Reuters) - Britain insisted on Sunday that the European Union should shift position to open the way to a post-Brexit trade pact, drawing a swift response from the bloc’s negotiator defending the union’s right to protect its interests.Negotiations are expected to continue on Monday, beyond a Sunday deadline set by the European Parliament, and a senior British government source described them as “difficult” because of the “significant differences” in position.With less than two weeks before Britain leaves the EU’s orbit, both sides are calling on the other to move to...WW…