It is "extraordinarily unlikely" that treason charges will be used against outspoken Islamic radicals, Lord Chancellor Lord Falconer has said.
Omar Bakri Mohammed is one of three who may be prosecuted
The Crown Prosecution Service's head of anti-terrorism is due to discuss the treason idea with Scotland Yard officers in the next few days.
Lord Falconer said individual decisions had to be taken on specific cases.
But he argued there were much better ways to bring criminal charges, such as incitement laws.
"I don't think anybody has seriously been suggesting that treason is really a runner," he told BBC Radio 4's Today programme.
The crime of betraying one's country has long been regarded as one of the most serious of offences.
Treason carries a penalty of life imprisonment. The death penalty for the offence was abolished only in 1998.
On Monday it was confirmed that Attorney General Lord Goldsmith and Director of Public Prosecutions Ken Macdonald have discussed action against three people.
A spokeswoman for the attorney general said: "No decision on charges has been made yet. The CPS will be looking at it to see if any offences have been committed."
Omar Bakri Mohammed, who has just travelled to Lebanon for a "few weeks", Abu Izzadeen and Abu Uzair were all expected to come under scrutiny.