According to Britain's Daily Telegraph on Monday, four detainees will not be released - though no specific charges have been made against them.
Martin Mubanga, Richard Belmar, Firoz Abbasi and Moazzam Begg cannot expect a hearing or release any time soon.
Azmat Begg, the father of detainee Moazzam, called indefinite detention unjust and said he was "shocked" that the fate of his son and hundreds of others was unclear after two years.
"We call ourselves the mother of civilization, we call ourselves champions of democracy, but what we are doing, we can see it ourselves."
Zumrati Juma, the mother of detainee Firoz Abbasi, also said Britain had not done enough to help resolve the prisoners' status.
Blunkett goes to US
The report comes as five other British prisoners are expected to be repatriated this week.
Home Secretary David Blunkett is heading to the United States, where he will finalise arrangements for the release of the five from the prison at the US naval base and have discussions on the remaining four.
"We call ourselves the mother of civilization, we call ourselves champions of democracy, but what we are doing, we can see it ourselves"
father of Guantanamo detainee
US officials quoted by the newspaper said some British citizens would not be released because they had trained in al-Qaida camps in Afghanistan and were taught how to make bombs and use urban guerrilla warfare techniques.
The US is holding more than 650 people captured since October 2001 in its war on terrorism at the Guantanamo base, with the vast majority neither charged, sentenced nor in contact with their family.