The Spanish Wine Federation have issued advice to the industry to reduce the threat of the UK’s potential no-deal exit from the EU.
It told its members to make advanced transportation plans and ensure wine is correctly labelled.
It comes as the value of the pound plummeted on Tuesday night following MPs’ vote on amendments to her Brexit deal.
This is after Rioja imports have been negatively affected by Brexit since early 2018.
Exports to the UK dropped 16% in the first 11 months of last year, while global markets saw a 10% slump, according to wine association Grupo Rioja.
He added: “Of course it could get worse in case of no deal.
“The sterling would further depreciate and the UK would turn into a third country with no custom agreement and probably higher duties.”
La Rioja is the largest European wine region in terms of exports to the UK.
In the first nine months of 2018, its wineries sold 32 million litres of vino to UK buyers – one third of its total global exports.
The UK is set to leave the EU on March 29 and Theresa May now has to negotiate her Brexit agreement with Brussels.