Government ministers confirmed on Tuesday that they are "considering" returning to the old blue passport after Brexit.
After a response to a written question in the House of Commons, Home Office minister Robert Goodwill said:
We are considering potential changes to the UK passport after the UK has left the European Union.
At this early stage we have not undertaken a detailed cost benefit analysis or made any decisions about what a future UK passport might look like.
The blue passports were introduced in 1921 but were scrapped in favour of the burgundy documents - used by other EU countries - that began in 1988.
In response to a campaign by the Sun to scrap the burgundy passport, the European Commission pointed out that Britain voluntarily signed up for the new colour and that a choice to change it is completely up to the British government.