This summer's upcoming Hyde Park concert by Black Sabbath could be their last, according to guitarist Tony Iommi.

"It could be the last ever Sabbath show,” Iommi told Metal Hammer. “I don't want it to be, but there's nothing really planned touring-wise after that show, so for all we know that could be it really."

The Barclaycard British Summer Time festival at London's Hyde Park takes place on Friday, July 4 with Sabbath as headliner, joined by Soundgarden and Motorhead among others. This is also the final date scheduled on the band's 2014 tour. It also sounds like any future touring plans will be less intensive: "To be honest I don't want to be touring to this extent too much longer, because it makes me feel so bad," explains Iommi.

Since being diagnosed in early 2012 with lymphoma, Iommi has undergone a series of treatments. He is currently awaiting an update on his current condition. "I'm at a stage now where I have no support, which means I have to see whether the cancer is coming back or if it's still there or what,” he said. “I just don't know. It's a bit of a worry. After we finish this tour I'll go in and have scan, so we'll see what that shows up.”

"Hyde Park will a great way to end the European tour," he adds. "We haven't made any specific plans as the gig is a way off yet, but I think it'll be special.”