LONDON, Aug. 9 (Xinhua) -- Britain's Home Secretary John Reid warned on Wednesday that the country was now facing its "most sustained period of severe threat since the end of World War II", Sky news reported.

    While addressing the think tank Demos, Reid said that although the police and security services were doing all they could to protect the public, they couldn't be sure of stopping terrorist attacks, the report said.

    He called for the wider society to help defend Britain from international terrorism, saying the government couldn't do it alone.

    The government had changed the way the security services worked, bringing in four new anti-terror acts since 2000. Some 1,000 people had been arrested for suspected terror offenses, of whom 154 had been charged and 60 were awaiting trial. In addition, at least four major terror plots in Britain had been foiled, the secretary said.

    However, the Home Office has been criticized for imprisoning some terror suspects without trial and for drawing up plans for a national identity card scheme.

    Reid also noted that Britain might have to modify its freedom laws in the short term in order to prevent their "misuse and abuse" by terrorists.

    He signaled further legislative changes, particularly to laws that prevent the deportation of terror suspects, saying "the laws have not caught up with our wars".

    He also described migration as the "greatest challenge" to the European Union, claiming that there was a need to get away from the notion that people who discuss this were somehow racist.

    "Our adversaries in international terrorism are completely unrestrained, including in their attempts to misuse our freedoms to undermine our free society," the home secretary warned. Enditem