* Johnson and Varadkar to meet in England
* Johnson: cautiously optimistic
* EU tells Britain: Make more concessions
By Elizabeth Piper and Guy Faulconbridge
LONDON, Oct 10 (Reuters) – Prime Minister Boris Johnson will meet his Irish counterpart on Thursday in a last-ditch attempt to revive a British proposal for a Brexit deal that the European Union said falls far short of what is needed for an orderly divorce.
Just three weeks before the United Kingdom is due to leave the world’s biggest trading bloc, it is still unclear on what terms it will leave or indeed whether it will become the first sovereign state to…