Britain's Guardian newspaper quoted US military papers as saying the men would have no lawyer, have limited rights to call witnesses and would be presumed to be enemy combatants.
"There is a rebuttable presumption that the government evidence ... is genuine and accurate," the Guardian quoted the military papers as saying.
The cases will be heard by three US military officers and hearsay evidence could be used against them, the newspaper added.
In a rare disagreement between the close allies, Britain's top legal officer has condemned the plans for military trials.
"While we must be flexible and be prepared to countenance some limitation of fundamental rights if properly justified and proportionate, there are certain principles on which there can be no compromise," Attorney General Lord Goldsmith said in a
speech in June.
"We in the UK have been unable to accept that the US military tribunals ... offer sufficient guarantees of a fair trial in accordance with international standards."
The type of trial chosen - military tribunal - will be a blow to Prime Minister Tony Blair who was said to have asked President George Bush for the four prisoners to be sent home.
The detainees' incarceration in
legal limbo has caused outrage
Blair's office has refused to comment on whether a direct appeal was made to Bush, but a lawyer acting for one of the detainees said the request had emerged from government papers filed in court.
The British Foreign Office would not comment on the Guardian story, but said its position on Guantanamo remained the same.
"In the absence of the prospect of a fair trial consistent with international standards, British detainees should be returned home," a spokeswoman said.
The Pentagon created the tribunals after a June US Supreme Court ruling that Guantanamo prisoners could go to US courts to seek their freedom.
The Guantanamo prison was set up in January 2002 to hold combatants captured in Afghanistan, and also houses others suspected of association with Usama bin Ladin's al-Qaida network.
"In the absence of the prospect of a fair trial consistent with international standards, British detainees should be returned home"
British Foreign Office
The detainees' long incarceration in legal limbo has outraged many in Britain, many of whom are also uncomfortable with the closeness of Blair's friendship with Bush.
Washington says the four Britons - Firoz Abbasi, Martin Mubanga, Richard Belmar and Muazzam Begg - pose a security threat.
Five other British citizens were released from Guantanamo in March and freed within a day by British police without any charges.