Business leaders could be among a wave of new ambassadors under plans by Jeremy Hunt to open up the diplomatic service.
In a speech on Wednesday, the foreign secretary is expected to say that for the first time non-civil servants could represent the UK government overseas.
The creation of the 335 new diplomatic positions will sit alongside 328 additional jobs in London and a further 329 other posts around the world.
There will also be 12 new embassies or missions, with a focus on Commonwealth nations as part of a drive from the UK to reengage with former colonies after Brexit.
Hunt is due to say: "The strength of our network is its professionalism, which has given us what I believe is the finest diplomatic service in the world.
“But we must never close our eyes to the approaches and skills of other industries."
When quizzed about the plans ahead of the speech, Hunt denied suggestions that cronyism could dictate which business people were given the plush roles.
He said: “There will be absolutely no conflict of interest allowed and anyone applying for these jobs will apply through normal Foreign Office processes so we can make sure that proper independence is protected.”
Hunt added: “There may be one or two posts where someone who is perhaps chief executive of a FTSE company, who has got strong links with another country, could do a brilliant job representing the UK, building up our trade with another country. We want the Foreign Office to be open to that kind of talent.”
The suggestion that non-civil servants could take up some of new the roles was welcomed by the CBI, with head of international trade, James Aston-Bell saying: “As the UK forges new trading relationships around the world - and at a moment when demand for Brand Britain has rarely been so high - it is absolutely the right moment for the Foreign and Commonwealth Office to harness the talent, experience and knowledge of business leaders by bringing them into diplomatic roles.”
The FDA union, which represents senior civil servants, was critical of the move. Dave Penman, the union’s general secretary warned business people might not understand the complexities of international relations.
He said: “The role of a diplomat in representing the UK’s interests abroad is much broader than simply trade, which is why they go through years of training and develop such a range of skills.”
The Foreign Office is also planning to step up language training in the department, with Gujarati, Kazakh and Kyrgyz among 20 new courses on offer.