King Charles III will open a session of Parliament on Tuesday for the first time as monarch, outlining the British government’s legislative priorities as part of a tradition-steeped ceremony that will test his skill at displaying the political neutrality for which his mother, Queen Elizabeth II, was famous.

Drafted by the prime minister, Rishi Sunak, but delivered by King Charles, the centerpiece speech is a constitutional oddity — and one that will be watched closely this year, as the new sovereign reads out a list of government bills that includes some policies likely to be sharply opposed to his personal views.

Among those are Mr. Sunak’s plan to exploit more of Britain’s oil and gas reserves in the North Sea. Although the Conservative government argues that it will still meet its net zero targets for 2050, the decision to license more fossil fuel extraction has angered campaigners against climate change — a cause close to the king’s heart for decades.

King Charles made his first major speech about the environment in 1970, at the age of just 21, and in recent years has been an increasingly vocal advocate for climate action. In a speech in France in September, he urged the world to “strive together to protect the world from our most existential challenge of all: that of global warming, climate change and the catastrophic destruction of nature.”

Still, few expect King Charles on Tuesday to show anything other than the poker face expected of a British monarch when he delivers the “King’s Speech,” an occasion less famous for politics than for protocol, elaborate royal regalia and intricate choreography.

“It’s an oddity we have kept because the ceremonial is part of the monarchy but the speech itself is just the government setting out its policies — that’s where the weirdness originates,” said Catherine Haddon, program director at the Institute for Government, an independent think tank.

The monarchy’s commitment to political neutrality was consolidated during Queen Elizabeth’s reign, and “everything we have seen suggests that Charles is looking to show continuity,” Ms. Haddon said.

The government has already confirmed that its legislative plans include measures to offer oil and gas licensing rounds each year as opposed to the current system where they take place periodically.

The Conservatives want to set up a political dividing line with the opposition Labour Party, which has said that while it would honor existing licenses for oil and gas exploitation in the North Sea, it would not grant any new ones if it wins power.

On Monday Downing Street said that it saw no contradiction between its proposal and the climate change goals championed by the king. Using British energy resources would allow net zero targets to be achieved in a “pragmatic way that doesn’t burden hard working families,” Mr. Sunak’s official spokesman said.

This is likely to be the last king’s speech before the next general election, which must be held by January 2025, and analysts believe the government will set out a raft of policies targeting its core voters.

Those could include measures designed to appeal to motorists whom Mr. Sunak has recently tried to woo. That followed his party’s success in holding onto a parliamentary seat in Uxbridge and South Ruislip earlier this summer after it campaigned against the expansion by Labour’s London mayor of a scheme that charges people more to drive older, more polluting, cars.

That prompted Mr. Sunak to weaken several environmental measures in September when he said that he would delay by five years a ban on the sale of gas and diesel cars and would also lower targets for replacing gas boilers.

On Tuesday the government plans to announce new legislation on crime that aims to ensure that offenders of the most serious crimes will stay in prison for longer and will be forced to face their victims in court.

In comments released by his office, Mr. Sunak said that “in the most despicable cases, these evil criminals must never be free on our streets again. Life needs to mean life.”

The government may also announce legislation to implement a gradual ban it has already promised on smoking. Under the proposal it would be illegal to sell cigarettes to those born after January 2009.

Some Britons are still getting accustomed to the idea of a king delivering a speech that, during her seven-decade long reign, was read on 67 occasions by Queen Elizabeth. King Charles was deputized for his mother in May 2022 when she was unable to attend because of her failing health, and read what was known then as the Queen’s Speech.

Queen Elizabeth spent a lifetime observing political neutrality, rarely letting slip her personal thoughts on any issue of contention.

But even she could not avoid speculation about her political views and, when she read the Queen’s Speech in 2017 but did not wear her crown, there were questions about whether the colors of her hat — blue embroidered with a pattern of yellow flowers that to some resembled the European Union flag — were a statement about Brexit.

During the many decades he has spent waiting to succeed her, King Charles, 74, has championed a variety of causes, from architecture to the environment.

Last week Buckingham Palace said King Charles will give an opening address at the COP 28 meeting, which begins later this month in Dubai.

But Ms. Haddon said that the fact that his views are so well known would probably make the king more scrupulous in appearing neutral. He might, she added, be more concerned with delivery than with the content of the speech.

Established in the late 14th century, the state opening marks the beginning of the parliamentary year. The modern ceremony dates to 1852 when a rebuilt Parliament reopened after a fire. The route within the building that King Charles is expected to follow was used by Queen Victoria.

Her relations with the politicians of the day were not always harmonious, particularly with William Gladstone, a prime minister who, she complained, “speaks to me as if I were a public meeting.” (In contrast, Benjamin Disraeli, a rival who also served as prime minister, flattered and charmed the queen.)

Early in her reign, Queen Victoria attended the state opening regularly but that had lapsed by the end of her time on the throne, when she often resisted requests from prime ministers to appear in person. Her successor, Edward VII, revived the state opening as a ceremonial occasion, including a procession in the state coach through the streets of London, and with the king, in full regalia, personally reading the speech from the throne.