Five British nationals held at Guantanamo Bay are expected to arrive back in the United Kingdom on Tuesday after being held for two years in legal limbo because of their suspected links to Al Qaeda terrorists.

The five to be released are Rhuhel Ahmed, 23, Asif Iqbal, 20, Shafiq Rasul, 25, Terek Dergoul, 23, Jamal Udeen, 36. All are expected to be held at an air force base near London where they will be interviewed by anti-terrorist officers before they are free.

But four others are expected to stay in Guantanamo Bay because they have been branded a continuing and 'serious threat' to US and British interests.

Sources in London say the four who will stay behind are Moazzam Beg, 36, from Birmingham; Feroz Abbasi, 23, from Croydon; Richard Belmar, 23, and Martin Mubanga, 29, both from London.

All four are accused of training at Al Qaeda camps in Afghanistan where they are said to have been taught bomb-making and assassination techniques. One of the four is also suspected of meeting Osama bin Laden.

The fate of the four remaining British suspects will be raised by British Home Secretary David Blunkett who is visiting the US this week to participate in an anti-terrorism summit.

Blunkett had previously criticised the US for the way it detained terrorist suspects, calling for all prisoners to be treated 'fairly and in a humane fashion'.

Blunkett's arrival in Washington coincides with a visit by British campaigners for justice, including Moazzam Beg's father, Azmat, who want the suspects to be released.

Moazzam Beg is expected to be among one of the first to be tried by military tribunal, a system that has been criticised by British human rights advocates.

Azmat Beg commented: "We are going to Washington to make them hear our voices. We want them to know that we are human beings."

His son and Abbasi are likely to be among the first to be tried by military tribunals, a system which has attracted criticism from politicians of all sides in Britain.

UK solicitor Louise Christian, representing the families of Abbasi and Mubanga, said the latest US allegations were 'outrageous when the detainees do not have a voice'. But a senior Washington official has told the British media, "If the British government had captured Luftwaffe pilots bombing London ... they would not have given them lawyers to argue that they were innocent."