Far-reaching constitutional reforms have come under fire from the Lord Chief Justice.
Lord Woolf comments are likely to be highly contentious
Lord Woolf said plans for a supreme court replacing the House of Lords as the top legal body will create a "second class institution.
He also singled out Lord Chancellor Lord Falconer for criticism.
And he said David Blunkett's plans to limit the right of appeal for asylum seekers was "fundamentally in conflict with the rule of law".
He said that plans to prevent access to the courts over asylum decisions could fuel a campaign for a written constitution and added that the proposals were a "blot on the reputation of ministers".
Lord Woolf's comments came during a speech at Cambridge University's law faculty.
He remarked that Lord Falconer, a close ally and former flatmate of Tony Blair, was a "cheerful chappie".
And he said that it was "regrettable" the lord chancellor found himself in a position where he should have responsibility for promoting changes to the right to appeal in Clause 11 of the Asylum and Immigration Bill.
"Immigration and asylum involve basic human rights," he argued.
"What areas of government decision-making would be next to be removed from the scrutiny of the courts?
"What is the use of courts if you cannot access them?
"The response of the government and the House of Lords to the chorus of criticism of Clause 11 will produce the answer to the question of whether our freedoms can be left in their hands under an unwritten constitution."
He said the reforms could lead to too much power residing with the Home Office.
A spokesman for Lord Falconer's department defended the government's plans for constitutional reform.
Lord Falconer was described as a "cheerful chappie"
"These proposals were only brought to Parliament after extensive consultation and agreement with senior members of the judiciary, including the lord chief
justice, the legal professions and the public," he said.
"Central to the bill is the principle that politicians have no place in the courtroom and judges have no place in Parliament.
"This separation of powers is
vital to maintain public confidence in political institutions."
On changes to the asylum appeals the spokesman said the status quo was "too long and too complex".
"This will be a fair and proportionate system that is fully compliant with human rights legislation," he said.
Meanwhile a Home Office spokesman said if Lord Woolf had constructive suggestions to make they would be happy to hear them.
"If we had been cowed by previous criticisms we would never have halved asylum claims or got life meaning life for murderers."
Lord Woolf said he was worried that Lord Falconer's department would become a "subsidiary of the Home Office".
"The result could be the Home Office being in a position to dictate the
agenda for the courts."
Lord Woolf - who is top judge in England and Wales - said that the supreme court would not be endowed with powers to rule legislation invalid as is the case in the US.
"This means that, though called a supreme court, it will not, in fact, be a supreme court," he said.
"Among supreme courts of the world, our supreme court will, because of its more limited role, be a poor relation."
"We will be exchanging a first class final court of appeal for a second class supreme court."
Lord Woolf then went on to attack the speed of change under New Labour saying that the constitution in this country had in the past grown slowly.
"There is hardly an institution performing functions of a public nature which has not been the subject of change," he said.