Theresa May has been urged to visit the factory of a UK security firm and explain why a French company is taking over their contract to make British passports.
De La Rue boss Martin Sutherland said the Prime Minister and Home Secretary Amber Rudd should look workers "in the whites of the eyes" and defend the decision.
His firm, which has produced UK passports for the last decade, said it lost in the tendering process to make new post-Brexit blue passports.
Gemalto, a French company, has reportedly won the bid by undercutting competitors by £50m.
Shares in De La Rue fell 6% after the news.
Mr Sutherland told Sky News: "I'm going to have to go and face those workers, look at them in the whites of the eyes and try and explain to them why the British Government thinks it's a sensible decision to buy French passports not British passports."
"I would actually like to invite Theresa May or Amber Rudd to come to my factory and explain to my dedicated workforce why they think this is a sensible decision to offshore the manufacture of a British icon."
He added the move amounted to "offshoring the manufacture of a British icon" because new passports would be "manufactured in France".
Leading Brexiteers have condemned the decision, with Commons Leader Andrea Leadsom saying she was "very sympathetic" to criticism.
Tory MP and former international development secretary Priti Patel also raged that it amounted to a "national humiliation".
A new contract was put out to tender for British passports after Brexit as the current one is due to run out.
It was put out across the EU under the bloc's single market rules.
The new manufacturer will be responsible for printing new blue-fronted travel documents, after Britain has left the EU and ditches the current standard burgundy.
Gemalto's bid will save taxpayers around £100m-120m, according to the Home Office.
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A spokeswoman said: "The preferred bidder has been selected following a rigorous, fair and open competition and all bidders were notified of the outcome last night.
"The chosen company demonstrated that they will be best able to meet the needs of our passport service with a high quality and secure product at the best value for money for our customers and the taxpayer.
"It's been the case since 2009 that we do not require passports to be manufactured in the UK. A proportion of passports have been made overseas since then with up to 20 percent of blank passport books currently produced in Europe with no security or operational concerns."