As neighbours of gin-loving Spaniards, it was only a matter of time before Portugal had its equal measure of the tonic boom – and this year’s coolest drink, apparently, is a port and tonic.

[Read more: 5 different ways you should be drinking port all year around]

But not the aged, tawny type that’s traditionally drunk at the end of the meal, especially at Christmas. You know; the nutty, sweet port that makes you feel all warm and cosy, and just a little bit tipsy.

We’re talking about the remarkably refreshing, golden coloured port made from a blend of white grapes that’s served well-chilled as an aperitif.

Graham's White port and tonic with ice and lemon (Graham's/PA)

Topped with tonic water, lots of ice and garnished with mint and lemon, it’s a brilliant thirst-quencher, which our continental cousins have been slurping for years.

But you don’t need a sun-drenched terrace overlooking the Douro River in the city of Porto (that gives the wine its name) to enjoy this Portuguese classic.

Versatile, stylish and right on trend with our growing appetite for petiscos (Portugal’s answer to tapas), salted almonds and olives, these crisp, dry wines can be enjoyed all year round as a lighter alternative to a G&T.

With a lower abv than classic white spirits such as gin and vodka (19.5% compared with 40%), they can be sipped in the sunshine with a few small plates, before moving on to the next ‘port of call’.

“White port is a sleeping giant and THE on-trend drink of the summer,” says Alex Down, Symington Family Estates, a leading producer of premium ports.

[Read more: How a G&T can keep mosquitoes at bay and 15 other things you didn’t know about gin]

“Already a staple in some of the trendiest cocktail bars across Europe, the UK has fallen in love with it and it’s now being enjoyed in summer cocktails, or as a classic ‘P&T’: Equal measures of Graham’s Fine White and good quality tonic, a few blocks of ice, a slice of lemon, a sprig of fresh mint, and you have the ultimate alternative to a run-of-the-mill G&T.”

Here’s everything you need to know…

What sort of cocktails is white port a good base for?

You can pretty much substitute white port in any cocktail that would ordinarily use white vermouth, as they’re both different types of fortified white wine. White port is particularly amazing in a white negroni.

Why is white port suddenly on our radar in the UK?

White port & tonic has been a classic aperitif in Portugal for decades. But now in the UK, as the gin market starts to saturate, consumers are naturally looking for alternatives – the next big thing.

Simple to make and delicious to drink, a P&T is a quirky, Mediterranean twist on your classic G&T, which is undoubtedly why it has taken off in such a big way.

Is white port pricey?

Most white ports sell at a retail price of below £20. Like any category of wine, some will be better than others and we recommend Graham’s Fine White Port Wine for its fresh, appealing flavours of tangy lime, almond and grapefruit.

Once opened, you can keep a bottle of white port chilled in the fridge for up to a week.