The Belgian region of Wallonia has vowed to block an EU trade deal with South America, foreshadowing the kind of barriers Britain will face as it tries to secure a quick agreement with the bloc.

Elio Di Rupo, Wallonia’s minister-president, said his administration, which took office in September, is against the EU-Mercosur deal, which negotiators struck in June last year.

“We are completely opposed, in the current state, to this treaty. For the Walloon government, it is no!” Mr Di Rupo, a centre-left social democrat told Belgian broadcaster RTBF.

Wallonia, which under the Belgian constitution gets to sign off any trade deals the national government does, notoriously rejected and held up the EU-Canada trade deal CETA after its parliament voted against it, only later relenting when concessions were made.

Mr Di Rupo said Wallonia, which is Belgium’s largely French-speaking region, would not accept the EU-Merosur deal unless South American producers were made to sign up to EU rules – as the bloc is asking Britain to do.

Bizarre: Boris Johnson drives 'Brexit' digger through boxes Show all 8 1 /8 Bizarre: Boris Johnson drives 'Brexit' digger through boxes Bizarre: Boris Johnson drives 'Brexit' digger through boxes Conservative party leader Boris Johnson drives a JCB through a fake wall POOL/AFP via Getty Images Bizarre: Boris Johnson drives 'Brexit' digger through boxes Prime Minister Boris Johnson during a visit to JCB cab manufacturing centre in Uttoxeter, while on the General Election campaign trail. PA Photo. Picture date: Tuesday December 10, 2019. See PA story POLITICS Election. Photo credit should read: Stefan Rousseau/PA Wire Stefan Rousseau PA Bizarre: Boris Johnson drives 'Brexit' digger through boxes Britain's Prime Minister and Conservative party leader Boris Johnson drives a Union flag-themed JCB, with the words "Get Brexit Done" inside the digger bucket, through a fake wall emblazoned with the word "GRIDLOCK", during a general election campaign event at JCB construction company in Uttoxeter, Staffordshire, on December 10, 2019. - Britain will go to the polls on December 12, 2019 to vote in a pre-Christmas general election. (Photo by Ben STANSALL / POOL / AFP) (Photo by BEN STANSALL/POOL/AFP via Getty Images) BEN STANSALL AFP via Getty Bizarre: Boris Johnson drives 'Brexit' digger through boxes Prime Minister Boris Johnson sits in a cab of a JCB during a visit to its cab manufacturing centre in Uttoxeter, while on the General Election campaign trail. PA Photo. Picture date: Tuesday December 10, 2019. See PA story POLITICS Election. Photo credit should read: Stefan Rousseau/PA Wire Stefan Rousseau PA Bizarre: Boris Johnson drives 'Brexit' digger through boxes Britain's Prime Minister and Conservative leader Boris Johnson drives a Union flag-themed JCB, with the words "Get Brexit Done" inside the digger bucket, through a fake wall emblazoned with the word "GRIDLOCK", during a general election campaign event at JCB construction company in Uttoxeter, Britain, December 10, 2019. Ben Stansall/AFP/Pool via REUTERS POOL REUTERS Bizarre: Boris Johnson drives 'Brexit' digger through boxes A sign made for a visit by Prime Minister Boris Johnson to the JCB cab manufacturing centre in Uttoxeter, while on the General Election campaign trail. PA Photo. Picture date: Tuesday December 10, 2019. See PA story POLITICS Election. Photo credit should read: Stefan Rousseau/PA Wire Stefan Rousseau PA Bizarre: Boris Johnson drives 'Brexit' digger through boxes Britain's Prime Minister and Conservative party leader Boris Johnson drives a Union flag-themed JCB, with the words "Get Brexit Done" inside the digger bucket, through a fake wall emblazoned with the word "GRIDLOCK", during a general election campaign event at JCB construction company in Uttoxeter, Staffordshire, on December 10, 2019. - Britain will go to the polls on December 12, 2019 to vote in a pre-Christmas general election. (Photo by Ben STANSALL / POOL / AFP) (Photo by BEN STANSALL/POOL/AFP via Getty Images) BEN STANSALL AFP via Getty Bizarre: Boris Johnson drives 'Brexit' digger through boxes Britain's Prime Minister and Conservative party leader Boris Johnson reacts as he sits in the cab of a drives a Union flag-themed JCB, after driving through a fake wall emblazoned with the word "GRIDLOCK", during a general election campaign event at JCB construction company in Uttoxeter, Staffordshire, on December 10, 2019. - Britain will go to the polls on December 12, 2019 to vote in a pre-Christmas general election. (Photo by Ben STANSALL / POOL / AFP) (Photo by BEN STANSALL/POOL/AFP via Getty Images) BEN STANSALL AFP via Getty

“We are for international trade but not under any conditions. We want environmental, social and health compliance criteria, valid at European level and in Belgium, to apply also to these countries,” he said.

The regional leader in particular raised objections to regulations on the meat imports. Britain hopes to secure a simultaneous trade deal with the US while it negotiates with the EU, and food exports are one of the main asks of American trade negotiators. The issue is likely to become a sticking point in UK-EU talks if Britain wishes to keep its markets open to American beef.

“There will be chemicals and antibiotics, while our European rules are strict. We ask that the rules, in the Mercosur countries, be the same as the European rules,” Mr Di Rupo said. “We have our objectives, our realities, and we want to defend Walloon beef.”

In the case of the Canada agreement, Wallonia only agreed to the deal after stronger safeguards on labour, environmental and consumer standards were offered.

EU trade deals that cover policy areas not solely reserved to Brussels have to be voted on by national parliaments, and sometimes regional parliaments, depending on the constitution of each member state.

These “mixed” deals can be a political minefield because each country and region has its own producer interests to think of before signing.

The more substantial a trade deal is, the more likely it is to cross beyond EU competencies and require signatures by individual member states. Deals that involve cross-border trade in services – as the UK has said it wants – are very likely to be mixed agreements and therefore subject to national parliaments’ votes.