BRUSSELS, Dec 17 (Reuters) - Two European Union diplomats and an official with the bloc said on Thursday they did not expect a new trade deal with Britain to come together by Friday, saying negotiators were still apart on the sensitive issue of fisheries.

A source with the European Parliament told Reuters separately that the bloc's Brexit negotiator, Michel Barnier, told lawmakers earlier on Thursday that a deal "in the coming days is possible but difficult especially on fisheries".

AFP reported Barnier as saying a deal was possible by Friday.

But EU diplomats, who spoke under condition of anonymity, said Barnier and his British counterpart, David Frost were honing in on fisheries in the most secretive, so-called tunnel talks.

They said that any agreement that could emerge would produce a "differentiated" system on fishing quotas, but did not expect that to happen by Friday. (Reporting by Gabriela Baczynska; Editing by Alex Richardson)