The move follows a difficult three years in power, during which May failed to deliver on Brexit, something she said would remain a source of “deep regret”.
Delivering a statement in Downing Street Friday, May said she had worked hard to honour wishes of the British people following the 2016 referendum.
“It is now clear to me that it is in the best interests of the country for a new prime minister to lead that effort,” she said.
The party’s eventual new leader will likely to push for a more decisive divorce deal.
A leadership contest will begin the week after May steps down.
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