European Union (EU) bosses want to control the UK’s post-Brexit trade policy as they fear a hard left Labour regime led by Jeremy Corbyn will clam down on free trade and competition.

Senior EU officials said they are insisting on a tough “level playing field mechanism” to guard against the potential policies of a socialist Labour government, which could nationalize utilities such as energy and restrict European firms access to Britain’s public services.

The development comes the Prime Minister Theresa May continues to push for a so-called “customs arrangement” with the bloc that critics say will keep the UK tied to many of the EU’s restrictive rules.

The EU is likely to push for some of former Prime Minister Margaret Thatcher’s privatization and free-market policies to be written into the Brexit deal, so EU firms can still bid for work in Britain.

A senior Brussels source involved in Brexit negotiations told The Times: “The idea that Conservatives would legislate a race to the bottom is a myth and no one really believes it, even if some Tories have helped create it.

“The real fear is state subsidies under a Jeremy Corbyn government.

“British policy has remained unchanged for generations but now there is a real chance of a left-wing government reversing it. We have to protect ourselves and the single market.”

The revelation comes as leading Brexiteer Jacob Rees-Mogg MP accused the Business Secretary Greg Clark of reviving ‘project fear’ after claiming the UK would be damaged if it perused a clean Brexit.

Asked why he was against staying tied to the bloc via a Mrs. May’s favored “customs partnership”, he told the ITV Peston on Sunday programme that it would in effect mean staying in the EU.

“The idea would be there would be a single point of entry for goods into the UK, any of which could then go on into the EU, subject to tariffs being reclaimed if they stayed in the UK,” he said.

“But for that to work they’ve got to meet all the single market regulations as well, and therefore the customs partnership is in a sense misnamed because it means single market as well as customs union and therefore we would not in effect be leaving the European Union.”