Interstate students will be welcome to take advantage of Victoria's free TAFE courses, but training sector insiders have warned the funding model may backfire.

The Labor government's 2018/19 put aside $172 million for almost 50 free TAFE and pre-apprenticeship training courses and another $304 million for new classes and 30,000 TAFE places.

Treasurer Tim Pallas said the money is designed to help alleviate the state's skills shortage.

There will be no residential restriction or other obligations for anyone wanting to study one of the courses, he confirmed on Wednesday.

"We live in a democracy, people have a free right of movement around this country and it's not going to be this government's intention to try and put a prohibition on that," Mr Pallas told 3AW.

"Turn up, get yourself an education (but) the reason they'll stay here, by the way, is there's all this work going on, I mean $13.7 billion worth of infrastructure this year."

He estimated an increased demand of about 30,000 places and said while some of the applicants may be from interstate, the vast majority will be Victorians.

The opposition has slammed the government for not limiting course participation to Victorians.

"(Premier Daniel Andrews') desperate attempt to beef up student numbers by offering free training to people from overseas and interstate will come at the expense of Victorian students," opposition training spokeswoman Steph Ryan said.

"This money should be invested to benefit Victorian workers and Victorian jobs."

The government later confirmed the free courses will not be open to international students.

The Australian Council for Independent Education and Training said its members are annoyed about missing out on the funds and the Victorian government is risking student outcomes.

The council cited a recent TAFE "crisis" in South Australia where guaranteed funding led to substandard courses and fewer enrolments because of higher overheads.

"We have seen firsthand in South Australia that this type of approach is not in the best interest of the students," Council chief executive Rod Camm said.

Mr Pallas, Mr Andrews and senior ministers started the post-budget sell on Wednesday with breakfasts, talkback radio, lunches and doorstops.