Liam Fox is under fire over £1m-plus plans to appoint new “trade commissioners” around the world, on gold-plated packages normally handed to the UK’s ambassadors.

The roles offer £120,000 salaries – akin to the pay for the most glittering ambassador jobs in France, Russia, Japan and at the United Nations – as well as lucrative home travel costs and private education for any children.

With the official title of “Her Britannic Majesty’s Trade Commissioners”, they will be charged with ensuring that post-Brexit Britain becomes a “global champion of free trade, in charge of its own independent trade policy”.

But Mr Fox, the International Trade Secretary, has been accused of quietly replicating the long-established roles of the existing ambassadors, with the taxpayer picking up the hefty bill.

Labour branded the move “a very expensive power grab”, while the Liberal Democrats said it “smacks of Liam Fox desperately seeking to be seen to be doing something, while his department treads water”.

Under EU rules, the UK is unable to negotiate and sign trade deals with non-EU countries while remaining in the bloc’s customs union.

Brussels is now insisting the UK must stay in the EU during the two-year transition period Theresa May hopes to secure from 2019, raising doubts about the job the commissioners will perform.

Nevertheless, the Department for International Trade (DIT) is advertising for nine such roles, with interviews planned for February and March.

They will “cover”; Africa, Asia-Pacific, China, Eastern Europe and Central Asia, Europe, Latin America, Middle East, North America and South Asia.

The adverts offer “a salary of up to £120,000”, setting out how the appointments are “subject to standard arrangements for those based overseas”.

Those “allowances” include “diplomatic service compensation allowances, travel package including transfer and flexible annual leave journeys for officer and dependants, cost of living allowance, child education allowance if relevant, and overseas transfer grant”.

The salaries alone tot up to more than £1m, and the department did not dispute that overall bill could top £1.5m once travel home and private school fees are added on.

Barry Gardiner, Labour’s Shadow International Trade Secretary, said expanding global trade was “essential”, but added: “Many will wonder how these new trade commissioners are supposed to relate to the work of the Foreign Office, whose embassies have been doing this work for many years with on the ground expertise.

“At a cost of well over a million pounds a year, this group of commissioners might be thought to be no more than a very expensive power grab by Liam Fox.”

Tom Brake, the Lib Dem Brexit spokesman, said: “However generous the package – from the salary to the boarding school fees – or the calibre of the commissioners, what impact will the commissioner for Africa or Europe be able to make on trade in a whole continent?

“Liam Fox would have done better to rely on our network of well-renowned ambassadors who are already tasked with promoting trade.”

And Peter Kyle, a Labour MP and supporter of the pro-EU Open Britain group, said: “We are paying the price for Liam Fox’s vanity.

“Public money is being wasted when we won’t be able to sign any new trade deals for years to come. And they will never be able to replace our trade with the EU, where nearly half our exports currently go.”

Foreign Office statistics show that the UK’s ambassadors in Paris, Moscow, Tokyo and elsewhere are paid either £120,000 or £125,000. Only Washington’s (£180,000) receives more.

But DIT rejected the charge, insisting the ambassadors provide “leadership and coordination for cross-Government activity”, rather than simply focusing on trade.

A spokesman said: “This allegation completely misunderstands the new and distinctive role of HM Trade Commissioners, who will provide overall leadership on trade for entire regions as the UK develops its own independent trade policy.

“As we leave the EU, we need a new approach to trade and investment promotion, putting exports at the heart of UK growth, while seeking inward and outward investment to promote UK prosperity – this requires a new, senior, commercial cadre to lead our trade work overseas.

“Unlike existing ambassadors, their work will include developing and delivering a regional trade plan in key global markets, which sets out DIT’s priorities across export and investment promotion, trade finance and trade policy.”

Mr Fox, an arch Brexiteer, has been the Cabinet’s leading champion of the UK having the ability to sign it own trade deals, promising a rapid and lucrative agreement with the US.

But that drive had already run into trouble even before the new Brussels guidelines, which are likely to prevent the UK signing its own trade deals until at least 2021.

Mr Fox lost a Cabinet battle over lowering UK food standards, after an outcry over opening the door to chlorine-soaked chickens and hormone-pumped beef from the US.

Michael Gove, the Environment Secretary, sided with critics who warned “a race to the bottom” could spell disaster for British farmers and animal protection.

Mr Fox also admitted Britain would have to seek to cut-and-paste existing EU trade deals with other countries because it lacks the “capacity” for fresh negotiations in the short term.