Controversial Downing Street aide Dominic Cummings has been spotted inside today's Nato summit – despite having resigned from the government.

Mr Cummings raised eyebrows after he was photographed inside the plenary session with world leaders on Wednesday morning, watching from the sidelines.

Like all special advisors he resigned from the government ahead of the election to prevent possible conflicts of interest – but still appears to be accompanying the prime minister to high profile international events representing the UK.

The sighting raises questions about the high-profile aide's influence in government and his relationship with Boris Johnson – as well as whether the spirit of election rules is being followed.

A Downing Street spokesperson said Mr Cummings' presence was approved by the Cabinet Office and claimed it was "standard practice" for advisors to return for international events taking place during the election period.

The spokesperson did not immediately provide any examples of other advisors being treated the same way when pressed.

The summit is taking place at the Grove hotel in Watford and is being attended by world leaders including Donald Trump, Emmanuel Macron, and Angela Merkel.