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Theresa May has said she will remain in Parliament as MP for Maidenhead after stepping down as prime minister.
Mrs May told the Commons she would sit on the backbenches after she leaves office at the end of July.
Her predecessor, David Cameron, stood down as an MP within months of leaving No 10, while Tony Blair triggered a by-election on the same day as quitting.
But other prime ministers, most notably Ted Heath, have remained in Parliament for decades after giving up power.
Mr Heath hung around in the Commons for 26 years after quitting as Tory leader in 1975, enjoying a famously tense and terse relationship with his successor, Margaret Thatcher.