James Slack, the political editor of the Daily Mail, is the frontrunner to become the new official spokesman to the prime minister.

The journalist is being lined up to replace Helen Bower, who is moving from Downing Street to the Foreign Office, where she will take up a new role as Boris Johnson’s director of communications.

If Slack is confirmed in the role, he will be following in the footsteps of his predecessor, James Chapman, who moved from the Mail to work for George Osborne. Chapman is now director of communications for the Brexit secretary, David Davis.

The Daily Mail has been a strong supporter of May since she announced her candidacy for the role of Conservative leader and prime minister, and has praised her dedication to Brexit.

Slack would join the team as a civil servant, in charge of No 10’s press office, and responsible for the twice daily briefings with political journalists in the Houses of Parliament.