LONDON, April 19 (Reuters) - Prime Minister Theresa May won parliament's backing for an early election on Wednesday, a vote she said would strengthen her hand in divorce talks with the European Union and help heal divisions in Britain.

May surprised allies and opponents on Tuesday when she announced her plan to bring forward an election that was not due until 2020, saying she needed to avoid a clash of priorities in the sensitive final stages of the two-year Brexit talks.

After addressing a rowdy session of the House of Commons, May won the support of 522 lawmakers in the 650-seat parliament for an election on June 8. Only 13 voted against.

With May seen winning a new five-year mandate and boosting her majority in parliament by perhaps 100 seats, the pound held close to six-and-a-half month highs on hopes she may be able to clinch a smoother, more phased departure from the EU and minimise damage to the UK economy.

"I believe that at this moment of enormous national significance there should be unity here in Westminster, not division," she said.

"A general election will provide the country with five years of strong and stable leadership to see us through the negotiations and ensure we are able to go on to make a success as a result, and that is crucial."

The former interior minister, who became prime minister without an election when her predecessor David Cameron quit after last year's referendum vote for Brexit, enjoys a runaway lead over the main opposition Labour Party in opinion polls.

She has also played up the strength of the economy, which has so far defied predictions of a slowdown - a key campaign theme that her Conservative Party will use to try to undermine Labour in the election.

A victory would give May a powerful mandate extending until 2022, long enough to cover the Brexit negotiations plus a possible transition period into new trading arrangements with the EU.

David Fuller's view

This was a bold, sensible move by Theresa May.  Initially, on taking over as Prime Minister following the Brexit vote, she did not wish to put the country through another General Election before full term.  However, Brexit remains inevitably controversial, albeit chosen by the UK electorate in the most democratic election that I have seen. 

With a majority of only 17 seats, which she inherited from Cameron, Mrs May found herself harried, mainly by dissatisfied Remainers who would inevitably weaken her negotiating position with the EU. The political gamble (there is always an element of uncertainty) was to call for a General Election which will hopefully give her a substantial overall majority. 

Today, Parliament voted to approve the election on 8^th June. Subsequently, we now hear Westminster talk of a ragbag Coalition of mostly Labour, Liberal Democrats and Scottish Nationalists, hoping to defeat the Conservatives.  This would presumably be led by the reassuring hand of Jeremy Corbyn, with Nickola Sturgeon pulling the strings from behind. One would have to swallow hard before voting for that gaggle of has beens, incompetents and single-issue advocates.