MP Roma Britnell said the South Australian government decision to prevent cross-border community members from accessing work and education as a "massive over correction".

"People who live in Nelson are reliant on Mount Gambier and Mount Gambier is reliant on them - they are people who provide services to that community and who contribute to its economy," Ms Britnell said.

"To ban them from going to work, doing the groceries or buying fuel because they live on the wrong side of a line on a map is a step too far."

The South West Coast MP said she had spoken with minister Jaclyn Symes who was handling the border closure issues for the Victorian Government and would continue to work with her to try and convince the South Australians that "it needs to be fixed immediately".

Ms Britnell said the South Australian Police Commissioner had indicated Coronavirus cases in Portland were one of the reasons for this decision, but she said that totally ignored the fact people from Portland were not able to enter South Australia anyway.

"Portland fell outside the 40-kilometre boundary South Australia put in place for cross-border communities," she said.

"South Australia also put in place strict testing requirements for anyone who had a permit to cross the border saying that it was required to stop the virus entering that state.

"I fail to see with those measures in place why these next steps are necessary."

Ms Britnell has also written to Victorian Premier Daniel Andrews asking him to make representations to South Australian Premier Steven Marshall and to ensure there were financial and practical supports put in place for cross-border community members who are going to be impacted by this decision.

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