SENIOR management at Edinburgh Castle have been forced into an embarrassing change of plans after public concern over a charity partner.

The famous landmark had initially planned to light up blue in support of an awareness campaign by controversial US-based Autism Speaks.

But a backlash on Twitter prompted a U-turn and castle owners have decided to illuminate the famous landmark in purple to mark neurodiversity.

One Twitter user said: "Just seen that Autism Speaks thinks @edinburghcastle is lighting it up blue on the 2nd of April. No, Edinburgh Castle. Autism Speaks is a hate organisation; every instance of #LightItUpBlue is an attack on the autistic community."

The Autism Speaks organisation has caused concern in the past for describing the condition as an “unmitigated disaster for families” and campaigning for a cure.

Opponents argue that such a stance stigmatises those with autism and called for quality services to help them live independent lives instead.

Set-up by American grandparents of a child with autism in 2005 with a donation from billionaire DIY magnate Bernie Marcus, the charity has also sparked controversy over its finances.

A spokeswoman for Historic Environment Scotland, which runs the castle, said: “Following feedback we received from the public, the Edinburgh Castle team reviewed the lighting request from Autism Speaks.

“We always aim to be inclusive for our staff and visitors, and on that basis the castle will be lit purple, as a symbol of neurodiversity.”

An Autism Speaks spokeswoman said: “The Light It Up Blue campaign promotes understanding and acceptance of people all across the vast autism spectrum, each of whom has a unique story to tell.”