Sweden imports around 1.3 million tonnes of rubbish each year, around half of it from Britain (and the other half from Norway), who also exports waste in great amounts to for example the Netherlands and Germany.

This is then converted to heat and electricity at so-called 'waste-to-energy' centres. Only one percent of waste produced in Sweden ever reaches landfill, with the remaining 99 percent recycled, reused or converted into energy through incineration.

In 2016 waste imported from other EU countries accounted for 20-25 percent of all the rubbish burned in Sweden that year.

READ ALSO: Why Sweden's waste imports may not be as 'green' as you think

But it is not yet clear how Brexit will affect the waste exported by Britain, who is expected to leave the European Union in only a few months' time.

“No, nobody knows. We and others have been looking at it, but we have no answer,” Weine Wiqvist, CEO of Sweden's municipal waste organization Avfall Sverige, told the TT newswire.

“We have to think about different scenarios, but it is really difficult. The Swedish Environmental Protection Agency, which signs off on import permits, doesn't know either,” said Niklas Amour, CEO of Bertling Enviro, a company involved in the international trade of waste-to-energy products.

They agree a potential end to waste exports will hit Britain the hardest.

“The Britons have said that there has to be rules for Brexit which enable continued exports because they don't have enough facilities of their own,” said Wiqvist, who hopes negotiators will be able to agree on solutions which would make it possible for British waste exports to continue.

“But if there's a hard Brexit the trade business will probably follow completely different rules.”

Sweden, however, is not reliant on British imports despite them currently playing a major role. There are plenty of other countries that would want to sell their rubbish, Amour argues. But he believes there will be a post-Brexit solution for Britain, perhaps using Norway as inspiration.

“We buy around half of the waste to Sweden from (Norway), and they're not part of the EU either. There are rules in place for them which means we can trade without custom duties. But there may be duties on waste from Britain,” he said.