Almost 20 years in the past, a wry younger human rights lawyer, Keir Starmer, told a documentary filmmaker that it had struck him as “odd” to obtain the title of Queen’s Counsel, “since I typically used to suggest the abolition of the monarchy.”

Mr. Starmer, now the chief of Britain’s Labour Party, has lengthy since disavowed his anti-monarchy statements as youthful indiscretions. In 2014, he knelt earlier than Charles, then the Prince of Wales, who tapped him on the shoulder with a sword and awarded him a knighthood.

If Sir Keir Starmer is swept into 10 Downing Road within the basic election subsequent week, as polls suggest he will be, he could find yourself extra politically in sync with Charles then the final two Conservative prime ministers, Rishi Sunak and Liz Truss, whose phrases have overlapped with the king’s reign.

On points together with climate change, housing, immigration and Britain’s relations with the European Union, specialists say, Mr. Starmer is more likely to discover frequent floor with a king who holds longstanding, often fervent, views on these points however is constitutionally barred from taking any position in politics.

“A Labour authorities beneath Keir Starmer will likely be extra attuned to the plight of individuals as a social situation,” mentioned Ed Owens, a historian who research the royal household. “These sorts of points have lengthy been on the radar of the king. There’s a gathering of minds by way of the social points at stake.”

If elected prime minister, Mr. Starmer would maintain a weekly meeting with Charles, the contents of which might be strictly between them. However individuals who know Buckingham Palace and Downing Road mentioned they might foresee a fruitful relationship between the 75-year-old monarch and the 61-year-old lawyer, who was knighted for his companies to legal justice as director of public prosecutions.

Past Mr. Starmer’s progressive politics, students mentioned that Charles would admire the soundness {that a} Labour authorities would possibly restore after the divisions, political upheaval and revolving door of leaders that adopted Brexit. In lower than two years on the throne, in any case, Charles may quickly be on his third prime minister.

“The monarchy seeks to be a unifying drive, holding the nation collectively, so it favors consensus relatively than division,” mentioned Vernon Bogdanor, a professor at Kings School London and an authority on constitutional monarchy. “That’s how the king sees his position.”

However Professor Bogdanor added, “Whereas his mom represented the wartime era, the king is extra consultant of the ’60s era.”

As sovereign, Charles doesn’t vote. However in his a long time as inheritor, he was outspoken about points he cared about, corresponding to organic farming and architecture. Often, his views on extra politically charged issues leaked out.

In 2022, Charles was reported to have criticized the Conservative authorities’s plan to place some asylum seekers on one-way flights to Rwanda as “appalling.” His feedback, made in a personal assembly, surfaced in The Instances of London and The Each day Mail weeks earlier than he represented Queen Elizabeth II at a gathering of Commonwealth international locations in Kigali, the Rwandan capital.

Clarence Home, the place Charles then had his workplace, declined to touch upon the experiences, nevertheless it didn’t deny them.

That prompted Boris Johnson, who was then the prime minister and proposed the Rwanda plan, to complain to Charles, in accordance with Mr. Johnson’s communications chief on the time, Guto Harri. In The Mail, he described Mr. Johnson “squaring as much as the prince and confronting him about what he — as unelected royalty — had mentioned in regards to the actions of a democratically elected authorities.”

Charles mentioned nothing about Rwanda after that. In April, after Parliament handed a revised model of the laws beneath Mr. Sunak, the king gave it his royal assent, as is his obligation, making it regulation. However Mr. Starmer has vowed {that a} Labour authorities would scrap the plan, calling it expensive and unworkable.

Local weather coverage is one other space the place the king would possibly discover a Labour authorities extra aligned along with his views. Ms. Truss requested Charles to not attend a U.N. local weather change convention in Egypt in 2022, depriving him of a platform to talk out on maybe his most cherished situation. Mr. Sunak later backtracked on a few of Britain’s emission-reduction targets, citing their onerous value throughout a cost-of-living disaster.

Labour, against this, introduced a inexperienced funding plan value 28 billion kilos, or about $35 billion, a 12 months, although it has since suspended the spending targets till Britain’s public funds enhance.

“It does sound like a brand new Labour authorities and Charles could be in step on these points,” Mr. Owens, the historian, mentioned. “However Labour has many advantageous phrases on the significance of a inexperienced agenda. Can they match these advantageous phrases with motion?”

Mr. Starmer’s devotion to the regulation may additionally spare the king the type of quandary his mom confronted in 2019. Mr. Johnson requested her to suspend, or prorogue, Parliament at a time when lawmakers have been maneuvering to delay his plan to drag Britain out of the European Union.

The queen assented, however the British Supreme Courtroom later ruled that the decision was unlawful. Critics assailed Mr. Johnson for placing Elizabeth in an untenable place, since she couldn’t defy an elected authorities. Ms. Truss raised comparable questions of governance when she proposed sweeping unfunded tax cuts in 2022, which set off a backlash within the monetary markets that sunk her premiership.

“These prime ministers have been in a position to run roughshod over the foundations,” Mr. Owens mentioned. “Usually talking, the monarchy doesn’t prefer it when an excessive amount of consideration is targeted on the Structure.”

As counterintuitive because it may appear, historians say that Elizabeth had extra cordial relations with Labour prime ministers than with Conservative ones. She was considered as particularly comfortable with Harold Wilson, a down-to-earth Yorkshireman, whereas her exchanges with Margaret Thatcher, a Conservative icon, have been said to be occasionally prickly.

To make sure, the early Labour Social gathering had an anti-monarchy pressure. Its first parliamentary chief, Keir Hardie — Mr. Starmer has the identical first identify — once wrote: “Despotism and monarchy are appropriate; democracy and monarchy are an unthinkable connection.”

Conservative political operatives dusted off the video of a younger Mr. Starmer and put it in advertisements suggesting that Labour hated the monarchy. However even earlier than Mr. Starmer took over, Labour had advanced right into a reliably constitutional get together. And analysts say that residual anti-monarchist emotions have been almost definitely swept away by his purge of the party’s hard left after he grew to become chief in 2020.

At Labour’s party conference in 2022, after the queen’s dying, the nationwide anthem was performed for the primary time. Mr. Starmer, the person who as soon as talked of abolishing the monarchy, raised his voice and sang, “God Save the King.”