Plans for Australia’s future submarines are expected to be unveiled in March next year.

But a claim by the former Morrison government that the nuclear power plants could be delivered by 2030 has been rejected by Labour’s Richard Marles.

“The truth about where the former government left us at the election time is that they were looking at a new nuclear submarine in the 2040s,” he said.

“There they were.

“We will be looking at every available option to try and bring that time forward. I think it would be very optimistic to bring it forward to eight years.”

He blamed his predecessors, leaving a “mess” that created a capacity gap between the retirement of the aging Collins class and the new ships.

“Their passivity, their failures, their bracelets actually opened up a capacity of 20 years (gap) and what now that is a gap that we want to do our best to close,” said Mr Marles.

The Defense nuclear submarine task force is halfway through its 18-month “scoping plan” to decide which ship Australia will go with.

Mr Marles said the study was on track to meet the deadline set by the former government and would then have a better idea of ​​whether an “interim” conventionally powered submarine will be needed to fill the gap.

“We need to look at options to bring all of that up… (and) how we can get that sub into service sooner rather than later,” he said.

Mr Marles’ comments come after Malaysia’s foreign minister expressed concern over the AUKUS agreement signed last year.

Saifuddin Abdullah has previously noted that the security arrangements could jeopardize a regional arms race.

In a joint press conference with Foreign Minister Penny Wong, he told reporters that he had informed Malaysia’s stance remained unchanged.

“In particular, we want to preserve the South China Sea and the region as a whole as a region of peace, trade and prosperity,” he said.

“We just had a very candid discussion about Aukus and I thank the (Australian) Foreign Secretary for explaining the government’s position. Malaysia’s position remains the same. I reported that to the Minister of Foreign Affairs.”

On Wednesday, Mr Marles – who is currently the acting prime minister while Anthony Albanese is abroad – sought to allay Malaysia’s concerns over nuclear proliferation.

“We are confident that the way we are going to pursue this will not. It’s a very important principle,” he says.

“No precedents are being set. It’s important that we are transparent about that as we modernize our military and spend more on defense.

“That we guide that with reassuring statesmanship so that our neighbors have a sense of confidence about why we are acquiring the capabilities that we are and for what purpose.”