Britain's outgoing Prime Minister Theresa May has warned that British political discourse is being driven down the wrong path.

In a major speech in London before she quits Downing Street next week, Mrs May said there had been a "coarsening" of debate which could be pushing the country to a "much darker place".

Mrs May said: "Today, an inability to combine principles with pragmatism and make a compromise when required seems to have driven our whole political discourse down the wrong path.

"It has led to what is, in effect, a form of absolutism.

"One which believes that if you simply assert your view loud enough and long enough you will get your way in the end.

"Or that mobilising your own faction is more important than bringing others with you.

"This is coarsening our public debate."

Mrs May said: "Some are losing the ability to disagree without demeaning the views of others.

"This descent of our debate into rancour and tribal bitterness, and in some cases even vile abuse at a criminal level, is corrosive to the democratic values which we should all be seeking to uphold."

She went on to say that: "Words have consequences.

"And ill words that go unchallenged are the first step on a continuum to ill deeds.

"Towards a much darker place where hatred and prejudice drive not only what people say but also what they do."

Conservative Party members have received their ballot papers which will see them chose between Boris Johnson or Jeremy Hunt to replace Mrs May as leader of the party.

The result of the ballot will be known next Tuesday.