Coe Vintners’ premium spirits arm Mangrove UK stocks 66 gins including Portobello Road on its wholesale list.
But Nick Gillett, commercial director at Coe Vintners, said: “We are turning down around two out of three gin brands that approach us.
“There will be a lot of brands falling out of the market because there’s now a lot of average brands in the market.”
He added: “I still see premium vodka growing, along with flavoured spirits and tequila.
“M&S are trying a global spirits range and really making an effort to educate consumers, so there is more choice out there.
"The signs are that it’s working. It’s a brave step and the right way to go.”