Proposed powers that could see UK terror suspects put under house arrest do not equate to a police state or internment, the lord chancellor said.
Lord Falconer said ministers had a balance to strike
Lord Falconer said a balance had to be struck to ensure people still enjoyed their basic liberties but also that they were protected from terrorism.
The plans follow a law lords' decision that detaining foreign terror suspects without trial breached human rights.
The new proposals were dubbed an "abuse of power" by the Law Society.
Appearing on the BBC's Breakfast with Frost programme Lord Falconer was asked whether he believed the new powers, which also allow curfews and tagging, would fall foul of human rights legislation.
That came after a report in the Sunday Times suggested that Home Secretary Charles Clarke has already been warned by the government's top legal adviser - Attorney General Lord Goldsmith - that the latest proposals could be overturned in the courts.
Lord Falconer said that he believed the new plans would "get through" and he argued that the threat since 11 September 2001 had been "different and much stronger than other terrorist threats".
"We as a government have got to protect the public from that threat but we've got to do it within the law."
The lord chancellor insisted there were checks and balances in the new proposals even if evidence was not heard in open court and if judges thought ministers were "going to far then they can strike it down".
"That is not internment. That is not a police state. That is a sensible measure," he said.
'Death and destruction'
Before the weekend, Prime Minister Tony Blair told the BBC he was aware of concerns over the destruction of traditional rights and freedoms.
"I pay great attention to the civil liberties of the country. But on the other hand, it is also right that there is a new form of global terrorism in our country, in every other European country and most countries around the world.
"They will cause death and destruction on an unlimited scale and they will and are trying to organise such terrorist activity in our own country. I just hope people get this in perspective."
Mr Clarke has said he wants to get as much information as possible about the terror threat into the public domain to allow a proper debate.
But he has conceded that some information would have to remain secret - and the public would have to trust the authorities to make sensible judgements about its use to justify detentions.
"A lot of the discussion around this revolves around the extent to which I as home secretary or the prime minister or the head of the security services or the commissioner of the Metropolitan Police can be trusted with the assessments that we make... and that's a real issue."
Chairman of the Bar Council, Guy Mansfield QC, told the BBC last week: "There's a real danger ... that what we end up doing is radicalising minorities.
"We saw it in Northern Ireland - you end up with sleepers in the population and we make this country, ironically, a more dangerous and not a safer place."
The plans were prompted by a Law Lords ruling that the imprisonment of 12 foreign suspects without trial breaches European human rights laws.
The Law Lords labelled the current regime "discriminatory" because it only applied to foreign nationals.
On Wednesday, Tory shadow home secretary David Davis described the new house arrest plans as "public internment".