Gfk released its consumer confidence index for the U.K. on late Thursday evening. GfK's U.K. consumer confidence index rose to -1 in May from -3 in April.

4 of 5 measures rose in May.

"Despite the tiny uptick this month, our confidence in economic matters, whether we look back or ahead 12 months, remains way below last year," Joe Staton, Head of Market Dynamics at GfK, said.

"Is it because the Brexit gremlins are hard at work? Almost certainly yes," he added.