Dublin Bus is to lose its distinctive colour scheme.
New livery will be introduced when a British firm starts operating 10% of the routes this year and the move is aimed at creating uniformity across the fleet.
The redesign will bear the logo 'Transport For Ireland'.
It's to coincide with Go Ahead coming into the market in October after it was awarded the contract to operate 24 routes.
In a statement, Dublin Bus said its brand is "iconic", "widely recognised" and a "significant asset to the state."
"The value of this citizen brand should be utilised to the maximum, building on its strong performance to drive further customer growth."
The statement went on to say that Dublin Bus "has not received an official proposal from the National Transport Authority on this matter."
"Dublin Bus will continue to work with the NTA to seek the best possible outcome for our customers, company and city."
Fianna Fail TD for Dublin John Lahart has told the Dail "Dublin Bus is part of the fabric of Dublin and I don't think it should be eviscerated so easily. Feedback shows the colours appeal to people with special needs and are a help to people who are visually impaired... I think the brand is worth fighting for."
The National Transport Authority says feedback from the public showed people felt it was important the appearance of the fleet be consistent across the network.
A spokesperson says it's not proposing to scrap the Dublin Bus branding, and the logo will still feature alongside Transport for Ireland's.
However the move is causing mounting concerns that Dublin Bus is on the road to eventually becoming privatised
Dermot O'Leary from the National Bus and Railworkers Union says "the NTA, as far as we're concerned, has been striving towards privatisation for a number of years now. They see themselves as a Transport For London model and are trying to replicate what's been done in London. And I'm not sure some of the companies in this country like Guinness and Aer Lingus would take kindly to their brand effectively being taken away from them."