Immigration in the UK is now out of control, a leading think tank has warned.

Britain, which is a former colonial power, may be in danger of being colonised itself, a report released by Civitas has concluded.

The controversial research, based on observations of the asylum appeals tribunals in the Greater London area, is likely to spark controversy.

Its author Myles Harris warned there are likely to be more incidents like the murder of a policeman by a suspected Algerian terrorist unless the Human Rights Act is repealed.

The report, "Tomorrow is Another Country", claims that current immigration procedures are lax and open to abuse by untruthful claimants and people-traffickers.

"The government's policy on immigration and asylum is weak, and even that weak policy is not enforced," said Harris."The only way to stop the abuses of our immigration law, regain control of our borders, and protect ourselves against the acts of terrorism which are associated with asylum seeking, is to repeal the Human Rights Act.

"The provisions of the act, or rather the way in which the act has been interpreted by the courts, make domestic policy on immigration all but unenforceable."

The report comes a day after David Blunkett expressed grave concern at the growing resentment towards asylum seekers in the UK.

In an interview with the New Statesman, the home secretary said: "I am deeply worried because genuine fears and concerns can so easily turn to a desire to find scapegoats...I am worried about people taking the law into their own hands."

Habib Rahman, the chief executive of the Joint Council for the Welfare of Immigrants, said: "This is loose talk - and dangerous talk...If there is a danger of vigilantism, it is his responsibility to ensure that the law is not broken."