LONDON (REUTERS) - Incoming Prime Minister Boris Johnson will appoint Dominic Cummings, the architect of Britain's Vote Leave campaign in the European Union referendum, as a senior adviser, a source for the new leader's team said on Wednesday (July 24).

Cummings is a political adviser and strategist who was part of the team that led the official 2016 campaign to leave the bloc. He has been highly critical of Theresa May's Brexit strategy.

The source confirmed the appointment of Cummings, who was found to be in contempt of Parliament earlier this year for failing to appear before lawmakers investigating "fake news" and the referendum.

Cummings, who headed the official Vote Leave campaign, has said he offered to give evidence.