Climate protesters have interrupted Opposition Leader Peter Dutton’s key foreign policy speech on Thursday and forced another shadow minister to abandon a press conference.

Security evicted the noisy protesters who heckled Dutton at the Lowy Institute in Sydney, and disturbed guests just minutes into his major set piece.

“Dutton, why are you lying to the Australian people about the cost of nuclear?” one protester called, while being led from a room.

“Why do you persist in promoting stupid ideas when your own party disagrees with your nuclear policy?”

Another protester fell onto seated guests while being led away by security.

Zack Schofield, one of the protesters from the Rising Tide group, said the party needed to distance itself from nuclear.

“We have just seen with ex-tropical cyclone Alfred what the climate crisis is already doing to Australian communities,” he said.

“We cannot afford more distraction and delay with unfeasible policies like nuclear.”

The Coalition has come under scrutiny for the cost of its plans to set up seven nuclear reactors across Australia, if it wins government at the next election.

Dutton’s speech was intended as a key policy moment, before the election, about the Coalition’s foreign policy platform.

He said he would seek a meeting with US President Donald Trump in his first days as prime minister and strengthen ties with the US, while also promising to stand up to Trump on issues affecting Australia.

“The United States remains our most important military partner and there is a lot of repair work to do in that relationship,” he said.

Dutton said Australia’s defence needed to be more self-reliant.

“If our sovereign interests are threatened, Australia must never be in a position where we are totally relying on friendly cavalry to come over the hill, and sadly, that is the reality for our country today,” he said.

“History has shown that acquiescence or appeasement ends in a cul-de-sac of strategic misfortune or worse, the government I lead will be fair and firm in its dealings with others.”

Dutton also offered a fierce criticism of Prime Minister Anthony Albanese’s response to the recent circumnavigation of Australia by a Chinese naval task force.

He said Albanese’s response was the “most weak and limp-wristed response” he’d seen.

China had engaged in “obvious show of force” but had also treated Australia with “contempt” because it did not give advance notice of the exercises, Dutton said.

He said a Coalition government would place the “national interest front and centre of our foreign policy” – and his first visit if he became PM would be to the US.

Later on Thursday, climate protesters also disrupted shadow treasurer Angus Taylor as he tried to speak about the economy.

As Taylor addressed the live television cameras, footage aired by Sky News Australia shows media crashers interrupting with their own questions before he called it off and walked away.

“You are talking about cost of living and this is a flagship policy that you are asking Australian citizens to fund billions and billions. Your own party is campaigning against nuclear power,” one man can be heard asking Taylor.

Chalmers is confronted on stage in Brisbane. Photo: Sky News screengrab

On Wednesday, Treasurer Jim Chalmers’ pre-budget speech was interrupted by a pair of protesters who accused the government of “turbocharging the climate crisis” by approving fossil fuel projects.

“What we’re trying to do is to strike the right balance, recognising that we can make ourselves an indispensable part of the global net-zero economy at the same time as we leverage some of our traditional strengths,” Chalmers said.

“There is a role, for example, for gas in the energy transformation.”

Rising Tide took credit for that action.

“Two brave Rising Tide legends … have absolutely smashed this action,” it wrote on Facebook.

“They called out the elephant in the room, which is the Labor Party’s ongoing approvals of new coal and gas – which are fuelling disasters like Cyclone Alfred and costing us all.”

-with AAP