In its pre-budget submission, the Law Council of Australia has asked the federal government for more than a billion dollars over the next four years to ensure Australians don't miss out on legal help.

"Legal assistance funding in Australia is abysmal and in need of urgent review. Some of our most vulnerable people are slipping through the cracks," council president Arthur Moses SC said.

He said $310 million a year would adequately fund for Legal Aid Commissions, community legal centres, Aboriginal and Torres Strait Islander legal services and family violence prevention legal services.

"(This) will come close to restoring the Commonwealth's share of funding for Legal Aid Commissions to 50 per cent," he said.

"Commonwealth legal aid funding is at its lowest in decades. In 1997 the federal government spent $11.22 per capita.

"Today, it is spending less than $8 per capita. Many living under the poverty line are ineligible."

The council also wants urgent funding boosts for family law courts.

"Families and children are having to wait up to three years, in many cases more, to have matters heard," Mr Moses said.

The federal budget will be delivered in four weeks time, and Treasurer Josh Frydenberg is expected to deliver the first surplus budget in 12 years.

Australian Associated Press