A weakening pound sterling currency in the run-up to the UK's Brexit referedum on European Union membership may put extra pressure on the pricing of Bordeaux 2015 en primeur wines, some merchants believe.

A relatively weak sterling may make Bordeaux 2015 en primeur wines from the eurozone more expensive for UK buyers, even if châteaux do not increase prices compared to last year.

It is too soon to predict prices for Bordeaux 2015. Vintage quality will play an important role, with critics set to taste the wines for the first time during en primeur week beginning 4 April.

But, sterling was this week 6% down against the euro versus the beginning of 2016, with £1 equivalent to €1.27 on Thursday morning, 16 March.

It was 9% down versus this time one year ago, ahead of the Bordeaux 2014 campaign.

Financial analysts believe the UK’s upcoming Brexit vote has exacerbated the situation. Swiss bank UBS has even forecast that the pound could fall to parity with the euro if Britons vote to leave the EU on 23 June.

‘Essentially anything that affects the exchange rate is going to have an effect on the success of the [Bordeaux 2015] campaign in England,’ Giles Cooper at BI, previously known as Bordeaux Index, told Jane Anson for her Decanter.com column on the Brexit vote, published today.

Max Lalondrelle, fine wine buying director at Berry Bros & Rudd, said the merchant was keen to get involved in Bordeaux 2015, but ‘the threat of Brexit will make us that bit more cautious about what we buy’.

Bordeaux’s en primeur system remains in a delicate state. Several years of difficult campaigns have hit merchant revenues and created a build-up of stocks.