By Zahra Khaliq The tea aisle in Sainsbury’s has been left half-empty as Britain faces a shortage of the nation’s favourite brew – due to supply issues caused by Houthi attacks in the Red Sea. Images of nearly empty shelves in one London store show top tea brands – including PG tips, red label and Yorkshire tea are almost gone – as they appear to have been snapped up by Brits stocking up ahead of the shortage.Tea lovers were earlier warned that they could struggle to snap up their favourite brew on supermarket shelves as Sainsbury’s alerted shoppers in some stores about nationwide problems aff…