Workers welcome subs decision

The decision to build 12 submarines in South Australia is a vote changer for locals, workers at Adelaide-based shipbuilder ASC say.

The company is expected to be the location for the bulk of the construction work in collaboration with defence shipbuilding group DCNS.

Electrician Shannon De Wit said like many of his colleagues he had doubts about the prospect of the work coming to SA but the "government had come through in the end".

"It's great news for South Australia, great news for all our jobs here and great news for our families," Mr De Wit told reporters after Prime Minister Malcolm Turnbull's announcement on Tuesday.

"Everyone was asking us what was going on down here and we had no answers.

"Now we do it's a big relief."

Asked if the decision was enough to be a vote changer in the upcoming federal election, Mr De Wit had little doubt.

"Definitely," he said.

His colleague Chris Bycoft said he was extremely happy and the announcement was good news for the future of South Australia.

He said it removed any doubts he had about having a long-term future in the defence shipbuilding industry.

Before Tuesday's announcement opinion polls suggested the Liberals might struggle in key South Australian seats if a decision to build the subs in SA was not made.