Legal aid is facing an "existential crisis" and must be streamlined to survive, according to Ken Clarke.
The Justice Secretary insisted it was "neither affordable nor sensible" to have a system that operated like the NHS by providing "for any need".
He also hit out at parts of the legal industry, claiming it was "failing" and "plagued by outdated methods and unreformed working practices".
Mr Clarke's comments come ahead of his contentious legal aid reforms going before the House of Lords on Tuesday, where they are expected to be given a rocky ride.
Tory grandee Lord Tebbit is attempting to stop proposals that would axe access to legal aid for children involved in medical negligence claims, according to the Guardian.
The bill would also remove legal aid in many areas, such as debt, housing, welfare and employment cases.
In an article for the Guardian, Mr Clarke said: "The backdrop to all this is that legal aid has never been, like the NHS, a service that largely provides for any need. Those most in need must be helped where they face serious injustice. But that does not mean that people must have taxpayer-funded legal help for whatever they want, whenever they want.
"This is neither affordable, nor sensible, when there are often better ways to resolve disputes than the winner-takes-all court room."
He added: "As my proposals are considered in the House of Lords, there should be no doubt that the current system is facing an existential crisis. Legal aid in England and Wales costs vastly more than other common law variants - twice as much per head as New Zealand's system for example."
"Our proposals protect legal aid where it matters most. It must be available where people's life, liberty or home is at stake, where they are at risk of serious physical harm or are victims of domestic violence, where they seek to challenge state action and where their children may be taken into care. The threat I want my reforms to pose is to a failing system, outdated methods and unreformed working practices, not to the needy."