Boris Johnson's media strategist Guto Harri leaves City Hall today

It was reported last Friday that Harri is set to leave his post in the coming months, but Harri has now revealed that today is his last day working for Johnson.

Harri said: ‘I’m leaving City Hall today. I’ve not signed on any dotted lines yet and am pondering a number of approaches. I need to catch my breath after four years before the next challenge.’

Harri added that it had been ‘a real joy and privilege working for such a charismatic, thoughtful and decent mayor. It’s been one hell of a laugh too!’

Harri is understood to have had an offer from News International, while another source has suggested that he has been offered a role in Downing Street.

A spokeswoman for News International told PRWeek last week: ‘We have not appointed a director of comms and are not commenting on rumours.’

Harri, a former BBC journalist, briefly worked as a senior consultant at Fleishman-Hillard in 2008, before joining Johnson's campaign after just two months.