Twitter is banning all political advertising ahead of the UK's general election in December.

Chief executive Jack Dorsey said the company believed the reach of political messages should be "earned not bought".

"Paying to increase the reach of political speech has significant ramifications that today’s democratic infrastructure may not be prepared to handle," he said.

The policy will come into effect on November 22, just weeks before the UK goes to the polls in a general election on December 12.

He said "deep fakes", where images and video are manipulated to distort reality, and micro-targeting of voters presented "challenges to civic discourse".

It will affect both adverts by individuals and pressure groups, with some limited exceptions, such as campaigns encouraging people to register to vote.

Full details have not yet been published. Mr Dorsey said the policy text would be released by November 15.