LIVERPOOL, England, Dec 12 (Reuters) - Britain told Iran on Sunday that there was still time for Tehran to save the nuclear deal but that this was the last chance for Iranian negotiators to come to the table with serious proposals. "This is the last chance for Iran to come to the negotiating table with a serious resolution to this issue, which has to be agreeing the terms of the JCPOA," British Foreign Secretary Liz Truss said. "This is their last chance and it is vital that they do so. We will not allow Iran to acquire a nuclear weapon."