Video report by Political Correspondents Libby Wiener
Theresa May has been urged to explain to British workers why the new post-Brexit blue passport will reportedly be made in France.
It comes after current British manufacturer De La Rue said the contract to manufacture the document, which Brexiteers see as a symbol of the UK's regained independence, is set to be awarded to Franco-Dutch firm Gemalto.
De La Rue boss Martin Sutherland said it was "disappointing and surprising" that his firm was "not allowed to compete" for the contact.
"Now this icon of British identity is going to be manufactured in France," he said.
Mr Sutherland said the Home Office had confirmed the move to him, although ministers denied the process was complete.
He also insisted his firm had been producing passports for the UK for the last 10 years "without a single hiccup" but had been "undercut on price"
He has called on the Prime Minister or Home Secretary Amber Rudd to explain their decision to his workers and said he would appeal.
Mr Sutherland said: "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."
The tender to produce the passport was put out across the EU under single market rules.
The Daily Telegraph reported that Gemalto undercut other bids by around £50 million.
Tory MP Sir Bill Cash, chairman of the Commons European Scrutiny Committee, branded the decision "completely wrong and unnecessary".
"Whatever the conditions which led to the decision in terms of pricing, the fact is that this is a symbolic event."
Liberal Democrat Brexit spokesman Tom Brake said "the blue passport saga is turning into a farce."
Unite national officer Louisa Bull said: "It wouldn't happen in France because of national security and it shouldn't happen in the UK.
"De La Rue is the UK's leading security printer making banknotes as well as passports sustaining thousands of decent jobs in the UK."
"Ministers need to reverse this decision and start supporting British business and UK workers through public procurement and an industrial strategy which is more than just soundbites," she added.
Culture Secretary Matt Hancock told the BBC's Today programme as far as he understood the procurement process was "not fully complete".
A Home Office spokeswoman said: "We are running a fair and open competition to ensure that the new contract delivers a high quality and secure product and offers the best value for money for customers.
"We do not require passports to be manufactured in the UK. A proportion of blank passport books are currently manufactured overseas, and there are no security or operational reasons why this would not continue."