The second day of a U.K. festival planned for May (13) has been pushed back until November (13) after two performers pulled out of the event.

The I'll Be Your Mirror festival in London was scheduled for the weekend of 4-5 May (13), and while the Saturday (04May13) performances - including the Yeah Yeah Yeahs and Black Lips - will take place as planned, Sunday's (05May13) sets have been delayed until 2 November (13).

The second day was set to feature Grizzly Bear, The Walkmen, Real Estate and Tortoise, but organisers reveal "two of the anticipated headliners pulled out".

Grizzly Bear are still part of the event, but it has not been revealed which artists will no longer be appearing. Bosses admit the 5 May (13) event was made "unviable" by the loss of the acts.

The full revised line-up will be announced in June (13).