Theresa May has accepted EU demands for a clause in the Brexit deal that will prevent them lowering employment or environmental standards.

The White Paper published by the government today includes the ‘non-regression clause’ that Yahoo revealed in March the EU was seeking to insert into the deal.

It states both parties will commit to “maintain current high standards through non-regression provisions in other areas, such as environmental and employment rules.”

It means ministers would not be able to axe EU legislation like the Working Time Directive, which guarantees the right to four weeks paid holiday, without endangering the trade deal.

May said in her Mansion House speech that the UK would not “enter a race to the bottom” with the EU on standards.

But she and a number of her ministers are on the record as criticising the policies which will now be protected.

When the UK signed up to the EU’s “social chapter” under the last Labour government, May said it was a “burden on business” that would put women out of work.

The Brexiteers who remain in her Cabinet have spoke out more recently against the policies May has now committed to keeping.

MORE: EU demands UK keeps workers’ rights in exchange for free trade deal

International trade secretary Liam Fox called the Working Time Directive a “burden” and transport secretary Chris Grayling said during the referendum campaign that it “increases costs for business.

And Brexit impact assessments published by the government revealed that deregulation in rights had been considered, although that was ultimately rejected.

UK government officials hope the commitment to the ‘non-regression clause’ will encourage the EU to offer them a more ambitious free trade deal as there will be fewer non-tariff barriers to trade.

Despite the concession, trade unions and environmental campaigners are still concerned about the prospect of the UK being left behind in terms of rights and standards.

Although the clause means no existing legislation can be axed in the UK, it does not mean the government will have to implement EU legislation introduced after Brexit.

TUC general secretary Frances O’Grady said: “Today’s offer on workers’ rights isn’t good enough. It provides no absolute guarantee for existing rights.

“And more importantly, this proposal would allow the rights of hardworking Brits to fall behind those of workers in other European countries.

“What we need is a common rule book on workers’ rights, now and into the future.”

The White Paper also promises to establish a “common rule book” for state aid – government support for private enterprise.

The Times reported in May that the EU was also seeking a “level playing field” on state aid because it feared a future Labour government could subsidise British businesses.