LONDON (Reuters) - Britain could leave the European Union toward the end of 2019, instead of early that year as expected by some politicians, reported the Sunday Times citing sources who have been briefed by ministers that Brexit departments were not ready.

The UK voted to leave the EU on June 23, but Prime Minister Theresa May has said she will not invoke "Article 50", the two-year formal process for divorcing the bloc, this year as the country needs time to prepare for negotiations.

Britain's international trade minister, Liam Fox, said in July that early next year could be the best time for Britain to trigger the divorce talks.

But Article 50 could be invoked later than that, City sources who had been privately warned by ministers told the Sunday Times, with any delays a result of new government departments set up to handle Brexit and international trade not yet being fully staffed.

Elections in France in May, and Germany in September, could also push back the timing of Britain triggering Article 50, reported the newspaper.

Any delay to the Brexit process is likely to draw criticism from the pro-leave side of May's Conservative party, with senior members such as John Redwood calling for a quick departure from the bloc.

(Reporting by Sarah Young; Editing by Sandra Maler)