The World Aviation Festival has stressed its commitment to a more sustainable future for the sector after climate protestors targeted the annual event in Lisbon today.

Red paint was sprayed across the entrance to the conference where around 5,000 delegates were gathered to discuss the key issues facing aviation today.

Inside, the main stage was stormed by protestors accusing the industry of killing the planet and demanding the end of private jets as a chief executive panel was underway.

Sir Tim Clark, chief executive of Emirates, had just said there should be more focus on what has been achieved.

He called for someone to champion what’s going on to governments, Non-Governmental Organisations] and “environmental zealots”.

“Someone has to say to them, we are trying very hard and the evidence is there. Look at the way we have moved in the last 20 years in terms of recognition of what’s been done.”

The protestors briefly interrupted the session before being escorted from the building by security.

A spokesperson for World Aviation Festival said: “There was a small protest at World Aviation Festival. This was quickly resolved.

“Whilst we accept there is much more to be actioned both in the aviation industry and beyond, we stand by our principles on sustainability and the companies we invite to the Festival.

“For the event we have taken steps to improve our sustainability ethos including having an official Carbon Partner, Chooose.

“Chooose help us easily calculate, track and offset our carbon footprint through supporting high-impact climate projects.”

Watch the short clip below of protestors being removed from the event: