Demi Lovato has been forced to cancel her London show that was due to take place tonight (June 10) at the O2 in Greenwich. 

Taking to Twitter, she wrote: "I write this through tears of frustration and sadness that I have to postpone my concert in London at the O2 tonight due to being very, very sick and with swollen vocal chords that were examined by an ENT (dr). 

"If I go on tonight and injure my vocal chords anymore I could potentially have to cancel the rest of my tour I'm so so so sorry to disappoint any of my fans in London that have traveled hours to be here by plane or car, and to all of the fans that got these tickets for their birthday, holiday or any other special occasion. It just breaks my heart to let you down.

"Just know I feel your frustration and I wouldn't do this unless I absolutely had to. For everyone who bought a ticket for tonight's show, I will see you for the rescheduled date of June 25th after Madrid and Rock in Rio."

Lovato's Tell Me You Love Me South American and Mexico tour dates were rescheduled in April due to production issues. Her Newark, New Jersey show was posptoned due to bad weather in March this year.

The tour started on February 26 this year and is due to end on November 27, 2018. 

The star slotted in a suprise performance of "Instruction" at Capital's Summertime Ball yesterday (June 9) in London's Wembley Stadium with Steflon Don and Jax Jones. Watch below: