Switch-On 2017: Star Trek and Harry Potter star Jason Isaacs helps Diversity turn on the Illuminations after top intergalactic effort

The 20,000-strong crowd had been told to expect a Star Trek-themed finale to this evening's celebrations, but were taken by surprise as the Harry Potter villain - who played Lucius Molfoy - appeared as his Star Trek: Discovery character Captain Lorca.

Diversity choreographer Ashley Banjo and his troupe attempted to pull the famous lever after a spectacular performance, but were forced to call on Captain Lorca for help after the power failed.

After some out-of-this world chatter, a laser beam shot down to bring the Tower to life and to fully charge the resort's electricity supply ready for the big moment, and another season of dazzling illuminations.

Jason, from Liverpool, played out his role from the bridge of the USS Discovery before telling the crowd: “Discovery out. Now go have some chips for me!”

Diversity's Ashley Banjo: 'There's a lot of pressure!'

Illuminations Switch-On 2017 LIVE BLOG: Film star makes shock appearance to help Diversity flick the switch and launch another dazzling season of Illuminations

Earlier in the evening, the crowd had been wowed by live performances from Conor Maynard, Sigala, R3wire & Varski, and the MTV Base Garage Anthems show. It was the second year running that Diversity had played a starring role in the event, which this year was hosted by MTV’s Becca Dudley.

Sigala took to the stage as a last-minute replacement for Louisa Johnson, who has contracted laryngitis and ordered to rest for the next 10 days.

Once the Switch-On ceremony was over, Example and DJ Wire headlined an hour-long party under the Lights.

The Switch-On concert opened with a Blackpool Introduces section, showcasing local talent and giving Blackpool & The Fylde College choir an opportunity to celebrate the college’s 125thbirthday on stage.

Cllr Gillian Campbell, Deputy Leader of Blackpool Council: “We are delighted that one of the world’s most iconic TV franchises played a starring role alongside Diversity in this year’s Illuminations Switch-On.

“A huge amount of work has gone on behind the scenes to produce another memorable Switch-On event and it is quite remarkable that we are now working in partnership alongside global brands such as Nickelodeon, MTV, Netflix and CBS.

“The whole event provided a magnificent spectacle to launch the 2017 Illuminations season.”