In his first major policy announcement as Home Secretary, Mr Johnson ditched a trial scheme that would have required some airport staff and pilots to carry the controversial cards.
The schemes, at Manchester Airport and London City Airport, will instead be voluntary.
He also ruled out ever requiring the public to own a card. Previously, ministers said ID cards could become compulsory once 80% of the population was covered.
The cards will still be compulsory for foreign workers, Mr Johnson said.
Mr Johnson said: "Holding an identity card should be a personal choice for British citizens - just as it is now to obtain a passport.
"Accordingly I want the introduction of identity cards for all British citizens to be voluntary and I have therefore decided that identity cards issued to airside workers, planned initially at Manchester and London City airports later this year, should also be voluntary."
Asked if the cards would ever be made compulsory he said: "No".
"If a future Government wanted to make them compulsory it would require primary legislation," he added.
Mr Johnson said he still believed the cards would help improve security at airports.
But he admitted the Government had allowed the perception that the cards would be a "panacea" that would stop terrorism.
Listing the benefits of the scheme at a press conference in central London, he did not at first mention tackling terrorism.
Instead he said the cards would help stop illegal working, people trafficking and ID fraud.
Mr Johnson said he was an "instinctive" supporter of ID cards and said he wanted to "accelerate" the delivery of the cards.
A pilot scheme covering Greater Manchester will be extended to the whole of the North West of England from early next year, Mr Johnson said.
Jim McAuslan, general secretary of the British Airline Pilots' Association (Balpa), said: "This is a sensible change of approach and one which we welcome.
"Balpa has always had aviation security high on its agenda and has a number of ideas on how we can improve airport security which we will be pursuing with the secretary of state for transport.
"But we have never seen the national ID card as an improvement to security and we are glad that the new Home Secretary has listened to us."
Balpa said that under the original plans, pilots would have been required to have a national ID card before they could apply for a pass enabling them to get to their aircraft.
The consequence of this would have been that individual pilots would have been forced to have an ID card or automatically lose their job, said the union.
Mr McAuslan added: "Balpa will be stressing to its members the new voluntary nature of the scheme. We will also be monitoring airport operators to ensure they stick to the new rules and don't bring in compulsion by the back door."
TUC general secretary Brendan Barber said: "This is a victory for union campaigning. Unions will be pleased that ministers will no longer be making it compulsory for pilots, cabin crew and baggage handlers at the two trial airports to apply for ID cards.
"Unions have had reservations about the pilot scheme from the very beginning, fearing that compulsory ID cards would add little to airport security, but could end up risking the jobs of individuals who refused to comply and deterring new recruits from applying for airport jobs in Manchester and London."
Shadow home secretary Chris Grayling accused the Government of an "absurd fudge".
"This decision is symbolic of a Government in chaos," he said.
"They have spent millions on the scheme so far - the Home Secretary thinks it has been a waste and wants to scrap it, but the prime minister won't let him.
"So we end up with an absurd fudge instead. This is no way to run the country."
When the ID cards were originally mooted, it was assumed they would eventually become compulsory, with supporters saying the full benefits would not be realised unless they were.
In an early review of the project, police forces said the advantages of the cards would be reduced unless people had to carry them.
Former Home Secretary Charles Clarke said cards could be made compulsory once 80% of the population already had them. Today's decision removes the potential for compulsion, while encouraging more people to volunteer for a card more quickly.
Around 3,500 people have already signed up to carry a card. Mr Johnson said he wanted more young people to carry the cards to help them prove their age.
He is also considering plans to give the cards away free to those over 75.
Anyone else wanting a card will pay £30 on top of the cost of having their biometric details taken. The estimated cost to the taxpayer is more than £5 billion over ten years.
Everyone who wants a card, or a biometric passport, will have their details stored on the national identity register.
Civil liberties groups said this amounted to a compulsory scheme.
Isabella Sankey, director of policy for Liberty, said: "The Home Secretary needs to be clear as to whether entry on to the National Identity Register will continue to be automatic when applying for a passport.
"If so, the identity scheme will be compulsory in practice. However you spin it, big ears, four legs and a long trunk still make an elephant. And this white elephant would be as costly to privacy and race equality as to our purses."
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